diff --git a/components/fpspreadsheet/tests/datetests.pas b/components/fpspreadsheet/tests/datetests.pas
index b6df89416..a888bf66c 100644
--- a/components/fpspreadsheet/tests/datetests.pas
+++ b/components/fpspreadsheet/tests/datetests.pas
@@ -302,7 +302,7 @@ var
   Row: Cardinal;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
+  TempFile:=NewTempFile;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -372,8 +372,7 @@ var
   ActualDateTime: TDateTime;
   ErrorMargin: TDateTime; //margin for error in comparison test
 begin
-  //ErrorMargin:=0.000000000000001;     // = 1E-15 = 9E-11 sec
-  ErrorMargin := 1E-5/(24*60*60*1000);  // = 10 nsec = 1E-8 sec   // 1 ns fails
+  ErrorMargin := 1E-5/(24*60*60*1000);  // = 10 nsec = 1E-8 sec (1 ns fails)
   if Row>High(SollDates) then
     fail('Error in test code: array bounds overflow. Check array size is correct.');
 
diff --git a/components/fpspreadsheet/tests/fonttests.pas b/components/fpspreadsheet/tests/fonttests.pas
index a80ff97bf..e9c01c964 100644
--- a/components/fpspreadsheet/tests/fonttests.pas
+++ b/components/fpspreadsheet/tests/fonttests.pas
@@ -132,7 +132,6 @@ var
   MyCell: PCell;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -160,6 +159,7 @@ begin
   CheckEquals(uffBold in MyCell^.UsedFormattingFields, true,
     'Test unsaved bold attribute, cell '+CellNotation(MyWorksheet,Row, Col));
 
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -228,7 +228,7 @@ var
   expectedValue: String;
   counter: Integer;
 begin
-  TempFile:=GetTempFileName;
+
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -237,8 +237,10 @@ begin
   MyWorkSheet:= MyWorkBook.AddWorksheet(FontSheet);
 
   // Write out all font styles at various sizes
-  for row := 0 to High(SollSizes) do begin
-    for col := 0 to High(SollStyles) do begin
+  for row := 0 to High(SollSizes) do
+    begin
+    for col := 0 to High(SollStyles) do
+    begin
       cellText := Format('%s, %.1f-pt', [AFontName, SollSizes[row]]);
       MyWorksheet.WriteUTF8Text(row, col, celltext);
       MyWorksheet.WriteFont(row, col, AFontName, SollSizes[row], SollStyles[col], scBlack);
@@ -255,6 +257,7 @@ begin
         'Test unsaved font style, cell ' + CellNotation(MyWorksheet,0,0));
     end;
   end;
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -269,7 +272,8 @@ begin
     fail('Error in test code. Failed to get named worksheet');
   counter := 0;
   for row := 0 to MyWorksheet.GetLastRowIndex do
-    for col := 0 to MyWorksheet.GetLastColIndex do begin
+    for col := 0 to MyWorksheet.GetLastColIndex do
+    begin
       if (AFormat = sfExcel2) and (counter = 4) then
         break;  // Excel 2 allows only 4 fonts
       MyCell := MyWorksheet.FindCell(row, col);
diff --git a/components/fpspreadsheet/tests/formattests.pas b/components/fpspreadsheet/tests/formattests.pas
index 6c97eea5d..e82b28713 100644
--- a/components/fpspreadsheet/tests/formattests.pas
+++ b/components/fpspreadsheet/tests/formattests.pas
@@ -165,7 +165,8 @@ begin
   SollNumberFormats[6] := nfPercentage;   SollNumberDecimals[6] := 0;
   SollNumberFormats[7] := nfPercentage;   SollNumberDecimals[7] := 2;
 
-  for i:=Low(SollNumbers) to High(SollNumbers) do begin
+  for i:=Low(SollNumbers) to High(SollNumbers) do
+  begin
     SollNumberStrings[i, 0] := FloatToStr(SollNumbers[i], fs);
     SollNumberStrings[i, 1] := FormatFloat('0', SollNumbers[i], fs);
     SollNumberStrings[i, 2] := FormatFloat('0.00', SollNumbers[i], fs);
@@ -194,7 +195,8 @@ begin
   SollDateTimeFormats[8] := nfCustom;          SollDateTimeFormatStrings[8] := 'nn:ss';
   SollDateTimeFormats[9] := nfTimeInterval;    SollDateTimeFormatStrings[9] := '';
 
-  for i:=Low(SollDateTimes) to High(SollDateTimes) do begin
+  for i:=Low(SollDateTimes) to High(SollDateTimes) do
+  begin
     SollDateTimeStrings[i, 0] := DateToStr(SollDateTimes[i], fs) + ' ' + FormatDateTime('t', SollDateTimes[i], fs);
     SollDateTimeStrings[i, 1] := DateToStr(SollDateTimes[i], fs);
     SollDateTimeStrings[i, 2] := FormatDateTime(fs.ShortTimeFormat, SollDateTimes[i], fs);
@@ -274,7 +276,6 @@ var
   Row, Col: Integer;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -283,11 +284,13 @@ begin
   MyWorkbook := TsWorkbook.Create;
   MyWorkSheet:= MyWorkBook.AddWorksheet(FmtNumbersSheet);
   for Row := Low(SollNumbers) to High(SollNumbers) do
-    for Col := ord(Low(SollNumberFormats)) to ord(High(SollNumberFormats)) do begin
+    for Col := ord(Low(SollNumberFormats)) to ord(High(SollNumberFormats)) do
+    begin
       MyWorksheet.WriteNumber(Row, Col, SollNumbers[Row], SollNumberFormats[Col], SollNumberDecimals[Col]);
       ActualString := MyWorksheet.ReadAsUTF8Text(Row, Col);
       CheckEquals(SollNumberStrings[Row, Col], ActualString, 'Test unsaved string mismatch cell ' + CellNotation(MyWorksheet,Row,Col));
     end;
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -301,7 +304,8 @@ begin
   if MyWorksheet=nil then
     fail('Error in test code. Failed to get named worksheet');
   for Row := Low(SollNumbers) to High(SollNumbers) do
-    for Col := Low(SollNumberFormats) to High(SollNumberFormats) do begin
+    for Col := Low(SollNumberFormats) to High(SollNumberFormats) do
+    begin
       ActualString := MyWorkSheet.ReadAsUTF8Text(Row,Col);
       CheckEquals(SollNumberStrings[Row,Col],ActualString,'Test saved string mismatch cell '+CellNotation(MyWorkSheet,Row,Col));
     end;
@@ -338,12 +342,12 @@ var
   Row,Col: Integer;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
   // Write out all test values
   MyWorkbook := TsWorkbook.Create;
   MyWorksheet := MyWorkbook.AddWorksheet(FmtDateTimesSheet);
   for Row := Low(SollDateTimes) to High(SollDateTimes) do
-    for Col := Low(SollDateTimeFormats) to High(SollDateTimeFormats) do begin
+    for Col := Low(SollDateTimeFormats) to High(SollDateTimeFormats) do
+    begin
       if (AFormat = sfExcel2) and (SollDateTimeFormats[Col] in [nfCustom, nfTimeInterval]) then
         Continue;  // The formats nfFmtDateTime and nfTimeInterval are not supported by BIFF2
       MyWorksheet.WriteDateTime(Row, Col, SollDateTimes[Row], SollDateTimeFormats[Col], SollDateTimeFormatStrings[Col]);
@@ -354,6 +358,7 @@ begin
         'Test unsaved string mismatch cell ' + CellNotation(MyWorksheet,Row,Col)
       );
     end;
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -367,7 +372,8 @@ begin
   if MyWorksheet = nil then
     fail('Error in test code. Failed to get named worksheet');
   for Row := Low(SollDateTimes) to High(SollDateTimes) do
-    for Col := Low(SollDateTimeFormats) to High(SollDateTimeFormats) do begin
+    for Col := Low(SollDateTimeFormats) to High(SollDateTimeFormats) do
+    begin
       if (AFormat = sfExcel2) and (SollDateTimeFormats[Col] in [nfCustom, nfTimeInterval]) then
         Continue;  // The formats nfFmtDateTime and nfTimeInterval are not supported by BIFF2
       ActualString := MyWorksheet.ReadAsUTF8Text(Row,Col);
@@ -414,7 +420,6 @@ var
   MyCell: PCell;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -424,9 +429,11 @@ begin
   MyWorkSheet:= MyWorkBook.AddWorksheet(AlignmentSheet);
 
   row := 0;
-  for horAlign in TsHorAlignment do begin
+  for horAlign in TsHorAlignment do
+  begin
     col := 0;
-    if AFormat = sfExcel2 then begin
+    if AFormat = sfExcel2 then
+    begin
       // BIFF2 can only do horizontal alignment --> no need for vertical alignment.
       MyWorksheet.WriteUTF8Text(row, col, CELLTEXT);
       MyWorksheet.WriteHorAlignment(row, col, horAlign);
@@ -435,8 +442,10 @@ begin
         fail('Error in test code. Failed to get cell.');
       CheckEquals(ord(horAlign),  ord(MyCell^.HorAlignment),
         'Test unsaved horizontal alignment, cell ' + CellNotation(MyWorksheet,0,0));
-    end else
-      for vertAlign in TsVertAlignment do begin
+    end
+    else
+      for vertAlign in TsVertAlignment do
+      begin
         MyWorksheet.WriteUTF8Text(row, col, CELLTEXT);
         MyWorksheet.WriteHorAlignment(row, col, horAlign);
         MyWorksheet.WriteVertAlignment(row, col, vertAlign);
@@ -451,6 +460,7 @@ begin
       end;
     inc(row);
   end;
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -461,7 +471,8 @@ begin
     MyWorksheet := MyWorkbook.GetFirstWorksheet;
     if MyWorksheet=nil then
       fail('Error in test code. Failed to get named worksheet');
-    for row :=0 to MyWorksheet.GetLastRowIndex do begin
+    for row :=0 to MyWorksheet.GetLastRowIndex do
+    begin
       MyCell := MyWorksheet.FindCell(row, col);
       if MyCell = nil then
         fail('Error in test code. Failed to get cell.');
@@ -475,7 +486,8 @@ begin
     if MyWorksheet=nil then
       fail('Error in test code. Failed to get named worksheet');
     for row :=0 to MyWorksheet.GetLastRowIndex do
-      for col := 0 to MyWorksheet.GetlastColIndex do begin
+      for col := 0 to MyWorksheet.GetlastColIndex do
+      begin
         MyCell := MyWorksheet.FindCell(row, col);
         if MyCell = nil then
           fail('Error in test code. Failed to get cell.');
@@ -530,7 +542,6 @@ var
   current: String;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -538,12 +549,14 @@ begin
   // Write out all test values
   MyWorkbook := TsWorkbook.Create;
   MyWorkSheet:= MyWorkBook.AddWorksheet(BordersSheet);
-  for col := Low(SollBorders) to High(SollBorders) do begin
+  for col := Low(SollBorders) to High(SollBorders) do
+  begin
     MyWorksheet.WriteUsedFormatting(row, col, [uffBorder]);
     MyCell := MyWorksheet.GetCell(row, col);
     Include(MyCell^.UsedFormattingFields, uffBorder);
     MyCell^.Border := SollBorders[col];
   end;
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -556,7 +569,8 @@ begin
     MyWorksheet := GetWorksheetByName(MyWorkBook, BordersSheet);
   if MyWorksheet=nil then
     fail('Error in test code. Failed to get named worksheet');
-  for col := 0 to MyWorksheet.GetLastColIndex do begin
+  for col := 0 to MyWorksheet.GetLastColIndex do
+  begin
     MyCell := MyWorksheet.FindCell(row, col);
     if MyCell = nil then
       fail('Error in test code. Failed to get cell');
@@ -611,7 +625,6 @@ var
   TempFile: string; //write xls/xml to this file and read back from it
   c, ls: Integer;
 begin
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -622,14 +635,18 @@ begin
 
   c := 0;
   ls := 0;
-  for row := 1 to 10 do begin
-    for col := 1 to 10 do begin
+  for row := 1 to 10 do
+  begin
+    for col := 1 to 10 do
+    begin
       MyWorksheet.WriteBorders(row*2, col*2, [cbNorth, cbSouth, cbEast, cbWest]);
-      for b in TsCellBorders do begin
+      for b in TsCellBorders do
+      begin
         MyWorksheet.WriteBorderLineStyle(row*2, col*2, b, SollBorderLineStyles[ls]);
         MyWorksheet.WriteBorderColor(row*2, col*2, b, SollBorderColors[c]);
         inc(ls);
-        if ls > High(SollBorderLineStyles) then begin
+        if ls > High(SollBorderLineStyles) then
+        begin
           ls := 0;
           inc(c);
           if c > High(SollBorderColors) then
@@ -638,7 +655,7 @@ begin
       end;
     end;
   end;
-
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -653,12 +670,15 @@ begin
     fail('Error in test code. Failed to get named worksheet');
   c := 0;
   ls := 0;
-  for row := 1 to 10 do begin
-    for col := 1 to 10 do begin
+  for row := 1 to 10 do
+  begin
+    for col := 1 to 10 do
+    begin
       MyCell := MyWorksheet.FindCell(row*2, col*2);
       if myCell = nil then
         fail('Error in test code. Failed to get cell.');
-      for b in TsCellBorder do begin
+      for b in TsCellBorder do
+      begin
         current := ord(MyCell^.BorderStyles[b].LineStyle);
         expected := ord(SollBorderLineStyles[ls]);
         CheckEquals(expected, current,
@@ -712,7 +732,6 @@ var
   lCol: TCol;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -720,11 +739,13 @@ begin
   // Write out all test values
   MyWorkbook := TsWorkbook.Create;
   MyWorkSheet:= MyWorkBook.AddWorksheet(ColWidthSheet);
-  for Col := Low(SollColWidths) to High(SollColWidths) do begin
+  for Col := Low(SollColWidths) to High(SollColWidths) do
+  begin
     lCol.Width := SollColWidths[Col];
     //MyWorksheet.WriteNumber(0, Col, 1);
     MyWorksheet.WriteColInfo(Col, lCol);
   end;
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -737,7 +758,8 @@ begin
     MyWorksheet := GetWorksheetByName(MyWorkBook, ColWidthSheet);
   if MyWorksheet=nil then
     fail('Error in test code. Failed to get named worksheet');
-  for Col := Low(SollColWidths) to High(SollColWidths) do begin
+  for Col := Low(SollColWidths) to High(SollColWidths) do
+  begin
     lpCol := MyWorksheet.GetCol(Col);
     if lpCol = nil then
       fail('Error in test code. Failed to return saved column width');
@@ -782,7 +804,6 @@ var
   Row: Integer;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -792,6 +813,7 @@ begin
   MyWorkSheet:= MyWorkBook.AddWorksheet(RowHeightSheet);
   for Row := Low(SollRowHeights) to High(SollRowHeights) do
     MyWorksheet.WriteRowHeight(Row, SollRowHeights[Row]);
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -804,7 +826,8 @@ begin
     MyWorksheet := GetWorksheetByName(MyWorkBook, RowHeightSheet);
   if MyWorksheet=nil then
     fail('Error in test code. Failed to get named worksheet');
-  for Row := Low(SollRowHeights) to High(SollRowHeights) do begin
+  for Row := Low(SollRowHeights) to High(SollRowHeights) do
+  begin
     ActualRowHeight := MyWorksheet.GetRowHeight(Row);
     // Take care of rounding errors
     if abs(ActualRowHeight - SollRowHeights[Row]) > 1e-2 then
@@ -851,7 +874,6 @@ var
   row: Integer;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -859,13 +881,15 @@ begin
   // Write out all test values
   MyWorkbook := TsWorkbook.Create;
   MyWorkSheet:= MyWorkBook.AddWorksheet(TextRotationSheet);
-  for tr := Low(TsTextRotation) to High(TsTextRotation) do begin
+  for tr := Low(TsTextRotation) to High(TsTextRotation) do
+  begin
     row := ord(tr);
     MyWorksheet.WriteTextRotation(row, col, tr);
     MyCell := MyWorksheet.GetCell(row, col);
     CheckEquals(ord(tr), ord(MyCell^.TextRotation),
       'Test unsaved textrotation mismatch, cell ' + CellNotation(MyWorksheet, row, col));
   end;
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -878,7 +902,8 @@ begin
     MyWorksheet := GetWorksheetByName(MyWorkBook, TextRotationSheet);
   if MyWorksheet=nil then
     fail('Error in test code. Failed to get named worksheet');
-  for row := 0 to MyWorksheet.GetLastRowIndex do begin
+  for row := 0 to MyWorksheet.GetLastRowIndex do
+  begin
     MyCell := MyWorksheet.FindCell(row, col);
     if MyCell = nil then
       fail('Error in test code. Failed to get cell');
@@ -919,7 +944,6 @@ var
   MyCell: PCell;
   TempFile: string; //write xls/xml to this file and read back from it
 begin
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -940,6 +964,7 @@ begin
   if MyCell = nil then
     fail('Error in test code. Failed to get word-wrapped cell.');
   CheckEquals(false, (uffWordWrap in MyCell^.UsedFormattingFields), 'Test unsaved non-wrapped cell mismatch, cell ' + CellNotation(MyWorksheet,0,0));
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
diff --git a/components/fpspreadsheet/tests/formulatests.pas b/components/fpspreadsheet/tests/formulatests.pas
index d921ebb66..5c91a2c52 100644
--- a/components/fpspreadsheet/tests/formulatests.pas
+++ b/components/fpspreadsheet/tests/formulatests.pas
@@ -106,7 +106,8 @@ begin
     MyWorksheet := GetWorksheetByName(MyWorkBook, SHEET);
   if MyWorksheet=nil then
     fail('Error in test code. Failed to get named worksheet');
-  for Row := 0 to MyWorksheet.GetLastRowIndex do begin
+  for Row := 0 to MyWorksheet.GetLastRowIndex do
+  begin
     cell := MyWorksheet.FindCell(Row, 1);
     if (cell <> nil) and (Length(cell^.RPNFormulaValue) > 0) then begin
       actual := MyWorksheet.ReadRPNFormulaAsString(cell);
@@ -155,8 +156,6 @@ var
   t: TTime;
   hr,min,sec,msec: Word;
 begin
-  TempFile := GetTempFileName;
-
   // Create test workbook
   MyWorkbook := TsWorkbook.Create;
   MyWorkSheet:= MyWorkBook.AddWorksheet(SHEET);
@@ -170,7 +169,7 @@ begin
     formula in column B. }
   Row := 0;
   {$I testcases_calcrpnformula.inc}
-
+  TempFile:=GetTempFileName;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
@@ -184,7 +183,8 @@ begin
   if MyWorksheet=nil then
     fail('Error in test code. Failed to get named worksheet');
 
-  for Row := 0 to MyWorksheet.GetLastRowIndex do begin
+  for Row := 0 to MyWorksheet.GetLastRowIndex do
+  begin
     formula := MyWorksheet.ReadAsUTF8Text(Row, 0);
     cell := MyWorksheet.FindCell(Row, 1);
     if (cell = nil) then
diff --git a/components/fpspreadsheet/tests/internaltests.pas b/components/fpspreadsheet/tests/internaltests.pas
index d0d098188..906d8faf9 100644
--- a/components/fpspreadsheet/tests/internaltests.pas
+++ b/components/fpspreadsheet/tests/internaltests.pas
@@ -30,12 +30,6 @@ type
   private
     procedure NeedVirtualCellData(Sender: TObject; ARow, ACol: Cardinal;
       var AValue:Variant; var AStyleCell: PCell);
-    // Gets new empty temp file and returns the file name
-    // Removes any existing file by that name
-    // Should be called just before writing to the file as
-    // GetTempFileName is used which does not guarantee
-    // file uniqueness
-    function NewTempFile: String;
   protected
     // Set up expected values:
     procedure SetUp; override;
@@ -79,19 +73,6 @@ uses
 const
   InternalSheet = 'Internal'; //worksheet name
 
-function TSpreadInternalTests.NewTempFile: String;
-var
-  tempFile: String;
-begin
-  TempFile := GetTempFileName;
-  if FileExists(TempFile) then
-  begin
-    DeleteFile(TempFile);
-    sleep(40); //e.g. on Windows, give file system chance to perform changes
-  end;
-  Result:=tempFile;
-end;
-
 procedure TSpreadInternalTests.GetSheetByIndex;
 var
   MyWorksheet: TsWorksheet;
@@ -347,12 +328,14 @@ begin
       col := 0;
       CheckEquals(Length(SollNumbers) + 4, worksheet.GetLastRowIndex+1,
         'Row count mismatch');
-      for row := 0 to Length(SollNumbers)-1 do begin
+      for row := 0 to Length(SollNumbers)-1 do
+      begin
         value := worksheet.ReadAsNumber(row, col);
         CheckEquals(SollNumbers[row], value,
           'Test number value mismatch, cell '+CellNotation(workSheet, row, col))
       end;
-      for row := Length(SollNumbers) to worksheet.GetLastRowIndex do begin
+      for row := Length(SollNumbers) to worksheet.GetLastRowIndex do
+      begin
         s := worksheet.ReadAsUTF8Text(row, col);
         CheckEquals(SollStrings[row - Length(SollNumbers)], s,
           'Test string value mismatch, cell '+CellNotation(workSheet, row, col));
diff --git a/components/fpspreadsheet/tests/numberstests.pas b/components/fpspreadsheet/tests/numberstests.pas
index 479cc9684..6c0192ec0 100644
--- a/components/fpspreadsheet/tests/numberstests.pas
+++ b/components/fpspreadsheet/tests/numberstests.pas
@@ -170,7 +170,6 @@ var
   TempFile: string; //write xls/xml to this file and read back from it
 begin
   //todo: add support for ODF format
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -185,6 +184,7 @@ begin
     ActualNumber:=MyWorkSheet.ReadAsNumber(Row,0);
     CheckEquals(SollNumbers[Row],ActualNumber,'Test value mismatch cell '+CellNotation(MyWorkSheet,Row));
   end;
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile, AFormat, true);
   MyWorkbook.Free;
 
diff --git a/components/fpspreadsheet/tests/spreadtestgui.lpi b/components/fpspreadsheet/tests/spreadtestgui.lpi
index 5fca12336..ece61fcfa 100644
--- a/components/fpspreadsheet/tests/spreadtestgui.lpi
+++ b/components/fpspreadsheet/tests/spreadtestgui.lpi
@@ -90,6 +90,7 @@
       <Unit3>
         <Filename Value="numberstests.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="numberstests"/>
       </Unit3>
       <Unit4>
         <Filename Value="manualtests.pas"/>
@@ -98,6 +99,7 @@
       <Unit5>
         <Filename Value="testsutility.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="testsutility"/>
       </Unit5>
       <Unit6>
         <Filename Value="internaltests.pas"/>
@@ -107,6 +109,7 @@
       <Unit7>
         <Filename Value="formattests.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="formattests"/>
       </Unit7>
       <Unit8>
         <Filename Value="colortests.pas"/>
@@ -115,6 +118,7 @@
       <Unit9>
         <Filename Value="fonttests.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="fonttests"/>
       </Unit9>
       <Unit10>
         <Filename Value="optiontests.pas"/>
diff --git a/components/fpspreadsheet/tests/stringtests.pas b/components/fpspreadsheet/tests/stringtests.pas
index 9a6660e4d..f9e46a003 100644
--- a/components/fpspreadsheet/tests/stringtests.pas
+++ b/components/fpspreadsheet/tests/stringtests.pas
@@ -149,7 +149,6 @@ var
   TempFile: string; //write xls/xml to this file and read back from it
 begin
   //todo: add support for ODF/LibreOffice format
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -164,6 +163,7 @@ begin
     ActualString:=MyWorkSheet.ReadAsUTF8Text(Row,0);
     CheckEquals(SollStrings[Row],ActualString,'Test value mismatch cell '+CellNotation(MyWorkSheet,Row));
   end;
+  TempFile:=NewTempFile;
   MyWorkBook.WriteToFile(TempFile,sfExcel8,true);
   MyWorkbook.Free;
 
@@ -204,7 +204,6 @@ begin
   LocalNormStrings[2]:=StringOfChar('z',MaxBytesBiff8+1); //problems should occur here
   LocalNormStrings[3]:='this text should be readable'; //whatever happens, this text should be ok
 
-  TempFile:=GetTempFileName;
   {// Not needed: use workbook.writetofile with overwrite=true
   if fileexists(TempFile) then
     DeleteFile(TempFile);
@@ -245,6 +244,7 @@ begin
     CheckTrue(TestResult,'Exception: '+ExceptionMessage);
   end;
   TestResult:=true;
+  TempFile:=NewTempFile;
   try
     MyWorkBook.WriteToFile(TempFile,sfExcel8,true);
   except
diff --git a/components/fpspreadsheet/tests/testsutility.pas b/components/fpspreadsheet/tests/testsutility.pas
index d1f6b4504..36aa9736d 100644
--- a/components/fpspreadsheet/tests/testsutility.pas
+++ b/components/fpspreadsheet/tests/testsutility.pas
@@ -37,8 +37,25 @@ function RowNotation(Worksheet: TsWorksheet; Row: Integer): String;
 // older fpspreadsheet versions that don't have that function
 function GetWorksheetByName(AWorkBook: TsWorkBook; AName: String): TsWorksheet;
 
+// Gets new empty temp file and returns the file name
+// Removes any existing file by that name
+// Should be called just before writing to the file as
+// GetTempFileName is used which does not guarantee
+// file uniqueness
+function NewTempFile: String;
+
 implementation
 
+function NewTempFile: String;
+begin
+  Result := GetTempFileName;
+  if FileExists(Result) then
+  begin
+    DeleteFile(Result);
+    sleep(40); //e.g. on Windows, give file system chance to perform changes
+  end;
+end;
+
 function GetWorksheetByName(AWorkBook: TsWorkBook; AName: String): TsWorksheet;
 var
   i:integer;