diff --git a/src/NzbDrone.Api/RootFolders/RootFolderModule.cs b/src/NzbDrone.Api/RootFolders/RootFolderModule.cs
index e87e581de..30303ab73 100644
--- a/src/NzbDrone.Api/RootFolders/RootFolderModule.cs
+++ b/src/NzbDrone.Api/RootFolders/RootFolderModule.cs
@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using FluentValidation;
 using NzbDrone.Core.RootFolders;
 using NzbDrone.Core.Validation.Paths;
@@ -17,7 +17,9 @@ public RootFolderModule(IRootFolderService rootFolderService,
                                 DroneFactoryValidator droneFactoryValidator,
                                 MappedNetworkDriveValidator mappedNetworkDriveValidator,
                                 StartupFolderValidator startupFolderValidator,
-                                FolderWritableValidator folderWritableValidator)
+                                SystemFolderValidator systemFolderValidator,
+                                FolderWritableValidator folderWritableValidator
+            )
             : base(signalRBroadcaster)
         {
             _rootFolderService = rootFolderService;
@@ -35,6 +37,7 @@ public RootFolderModule(IRootFolderService rootFolderService,
                            .SetValidator(mappedNetworkDriveValidator)
                            .SetValidator(startupFolderValidator)
                            .SetValidator(pathExistsValidator)
+                           .SetValidator(systemFolderValidator)
                            .SetValidator(folderWritableValidator);
         }
 
@@ -60,4 +63,4 @@ private void DeleteFolder(int id)
             _rootFolderService.Remove(id);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NzbDrone.Api/Series/SeriesModule.cs b/src/NzbDrone.Api/Series/SeriesModule.cs
index 0b33b9ee3..20c5d8ecb 100644
--- a/src/NzbDrone.Api/Series/SeriesModule.cs
+++ b/src/NzbDrone.Api/Series/SeriesModule.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using FluentValidation;
@@ -45,6 +45,7 @@ public SeriesModule(IBroadcastSignalRMessage signalRBroadcaster,
                             SeriesExistsValidator seriesExistsValidator,
                             DroneFactoryValidator droneFactoryValidator,
                             SeriesAncestorValidator seriesAncestorValidator,
+                            SystemFolderValidator systemFolderValidator,
                             ProfileExistsValidator profileExistsValidator
             )
             : base(signalRBroadcaster)
@@ -71,6 +72,7 @@ ProfileExistsValidator profileExistsValidator
                            .SetValidator(seriesPathValidator)
                            .SetValidator(droneFactoryValidator)
                            .SetValidator(seriesAncestorValidator)
+                           .SetValidator(systemFolderValidator)
                            .When(s => !s.Path.IsNullOrWhiteSpace());
 
             SharedValidator.RuleFor(s => s.ProfileId).SetValidator(profileExistsValidator);
diff --git a/src/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj b/src/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj
index 3f2465279..a88ef4945 100644
--- a/src/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj
+++ b/src/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj
@@ -402,6 +402,7 @@
     <Compile Include="TvTests\ShouldRefreshSeriesFixture.cs" />
     <Compile Include="UpdateTests\UpdatePackageProviderFixture.cs" />
     <Compile Include="UpdateTests\UpdateServiceFixture.cs" />
+    <Compile Include="ValidationTests\SystemFolderValidatorFixture.cs" />
     <Compile Include="XbmcVersionTests.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/NzbDrone.Core.Test/ValidationTests/SystemFolderValidatorFixture.cs b/src/NzbDrone.Core.Test/ValidationTests/SystemFolderValidatorFixture.cs
new file mode 100644
index 000000000..39a7c68e4
--- /dev/null
+++ b/src/NzbDrone.Core.Test/ValidationTests/SystemFolderValidatorFixture.cs
@@ -0,0 +1,74 @@
+using System;
+using System.IO;
+using FizzWare.NBuilder;
+using FluentAssertions;
+using NUnit.Framework;
+using NzbDrone.Core.Test.Framework;
+using NzbDrone.Core.Tv;
+using NzbDrone.Core.Validation.Paths;
+using NzbDrone.Test.Common;
+
+namespace NzbDrone.Core.Test.ValidationTests
+{
+    public class SystemFolderValidatorFixture : CoreTest<SystemFolderValidator>
+    {
+        private TestValidator<Series> _validator;
+
+        [SetUp]
+        public void Setup()
+        {
+            _validator = new TestValidator<Series>
+                            {
+                                v => v.RuleFor(s => s.Path).SetValidator(Subject)
+                            };
+        }
+
+        [Test]
+        public void should_not_be_valid_if_set_to_windows_folder()
+        {
+            WindowsOnly();
+
+            var series = Builder<Series>.CreateNew()
+                                        .With(s => s.Path = Environment.GetFolderPath(Environment.SpecialFolder.Windows))
+                                        .Build();
+
+            _validator.Validate(series).IsValid.Should().BeFalse();
+        }
+
+        [Test]
+        public void should_not_be_valid_if_child_of_windows_folder()
+        {
+            WindowsOnly();
+
+            var series = Builder<Series>.CreateNew()
+                                        .With(s => s.Path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Windows), "Test"))
+                                        .Build();
+
+            _validator.Validate(series).IsValid.Should().BeFalse();
+        }
+
+        [Test]
+        public void should_not_be_valid_if_set_to_bin_folder()
+        {
+            MonoOnly();
+
+            var series = Builder<Series>.CreateNew()
+                                        .With(s => s.Path = "/bin")
+                                        .Build();
+
+            _validator.Validate(series).IsValid.Should().BeFalse();
+        }
+
+        [Test]
+        public void should_not_be_valid_if_child_of_bin_folder()
+        {
+            MonoOnly();
+
+            var series = Builder<Series>.CreateNew()
+                                        .With(s => s.Path = "/bin/test")
+                                        .Build();
+
+            _validator.Validate(series).IsValid.Should().BeFalse();
+        }
+    }
+}
diff --git a/src/NzbDrone.Core/MediaFiles/MediaFileDeletionService.cs b/src/NzbDrone.Core/MediaFiles/MediaFileDeletionService.cs
index 29066f08f..70c9a5a75 100644
--- a/src/NzbDrone.Core/MediaFiles/MediaFileDeletionService.cs
+++ b/src/NzbDrone.Core/MediaFiles/MediaFileDeletionService.cs
@@ -21,16 +21,19 @@ public class MediaFileDeletionService : IDeleteMediaFiles, IHandleAsync<SeriesDe
         private readonly IDiskProvider _diskProvider;
         private readonly IRecycleBinProvider _recycleBinProvider;
         private readonly IMediaFileService _mediaFileService;
+        private readonly ISeriesService _seriesService;
         private readonly Logger _logger;
 
         public MediaFileDeletionService(IDiskProvider diskProvider,
                                         IRecycleBinProvider recycleBinProvider,
                                         IMediaFileService mediaFileService,
+                                        ISeriesService seriesService,
                                         Logger logger)
         {
             _diskProvider = diskProvider;
             _recycleBinProvider = recycleBinProvider;
             _mediaFileService = mediaFileService;
+            _seriesService = seriesService;
             _logger = logger;
         }
 
@@ -76,6 +79,26 @@ public void HandleAsync(SeriesDeletedEvent message)
         {
             if (message.DeleteFiles)
             {
+                var series = message.Series;
+                var allSeries = _seriesService.GetAllSeries();
+
+                foreach (var s in allSeries)
+                {
+                    if (s.Id == series.Id) continue;
+
+                    if (series.Path.IsParentPath(s.Path))
+                    {
+                        _logger.Error("Series path: '{0}' is a parent of another series, not deleting files.", series.Path);
+                        return;
+                    }
+
+                    if (series.Path.PathEquals(s.Path))
+                    {
+                        _logger.Error("Series path: '{0}' is the same as another series, not deleting files.", series.Path);
+                        return;
+                    }
+                }
+
                 if (_diskProvider.FolderExists(message.Series.Path))
                 {
                     _recycleBinProvider.DeleteFolder(message.Series.Path);
diff --git a/src/NzbDrone.Core/NzbDrone.Core.csproj b/src/NzbDrone.Core/NzbDrone.Core.csproj
index 8b45694d3..0aa6fef7c 100644
--- a/src/NzbDrone.Core/NzbDrone.Core.csproj
+++ b/src/NzbDrone.Core/NzbDrone.Core.csproj
@@ -1182,6 +1182,7 @@
     <Compile Include="Validation\NzbDroneValidationFailure.cs" />
     <Compile Include="Validation\NzbDroneValidationResult.cs" />
     <Compile Include="Validation\NzbDroneValidationState.cs" />
+    <Compile Include="Validation\Paths\SystemFolderValidator.cs" />
     <Compile Include="Validation\Paths\MappedNetworkDriveValidator.cs" />
     <Compile Include="Validation\Paths\DroneFactoryValidator.cs" />
     <Compile Include="Validation\Paths\FolderWritableValidator.cs" />
diff --git a/src/NzbDrone.Core/Validation/Paths/SeriesAncestorValidator.cs b/src/NzbDrone.Core/Validation/Paths/SeriesAncestorValidator.cs
index c91560873..850118a0d 100644
--- a/src/NzbDrone.Core/Validation/Paths/SeriesAncestorValidator.cs
+++ b/src/NzbDrone.Core/Validation/Paths/SeriesAncestorValidator.cs
@@ -1,4 +1,4 @@
-using System.Linq;
+using System.Linq;
 using FluentValidation.Validators;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Tv;
@@ -10,7 +10,7 @@ public class SeriesAncestorValidator : PropertyValidator
         private readonly ISeriesService _seriesService;
 
         public SeriesAncestorValidator(ISeriesService seriesService)
-            : base("Path is an ancestor of an existing path")
+            : base("Path is an ancestor of an existing series")
         {
             _seriesService = seriesService;
         }
@@ -22,4 +22,4 @@ protected override bool IsValid(PropertyValidatorContext context)
             return !_seriesService.GetAllSeries().Any(s => context.PropertyValue.ToString().IsParentPath(s.Path));
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NzbDrone.Core/Validation/Paths/SystemFolderValidator.cs b/src/NzbDrone.Core/Validation/Paths/SystemFolderValidator.cs
new file mode 100644
index 000000000..a7af763cb
--- /dev/null
+++ b/src/NzbDrone.Core/Validation/Paths/SystemFolderValidator.cs
@@ -0,0 +1,92 @@
+using System;
+using FluentValidation.Validators;
+using NzbDrone.Common.EnvironmentInfo;
+using NzbDrone.Common.Extensions;
+
+namespace NzbDrone.Core.Validation.Paths
+{
+    public class SystemFolderValidator : PropertyValidator
+    {
+        public SystemFolderValidator()
+            : base("Is {relationship} system folder {systemFolder}")
+        {
+        }
+
+        protected override bool IsValid(PropertyValidatorContext context)
+        {
+            var folder = context.PropertyValue.ToString();
+
+            if (OsInfo.IsWindows)
+            {
+                var windowsFolder = Environment.GetFolderPath(Environment.SpecialFolder.Windows);
+                context.MessageFormatter.AppendArgument("systemFolder", windowsFolder);
+
+                if (windowsFolder.PathEquals(folder))
+                {
+                    context.MessageFormatter.AppendArgument("relationship", "set to");
+
+                    return false;
+                }
+
+                if (windowsFolder.IsParentPath(folder))
+                {
+                    context.MessageFormatter.AppendArgument("relationship", "child of");
+
+                    return false;
+                }
+            }
+            else if (OsInfo.IsOsx)
+            {
+                var systemFolder = "/System";
+                context.MessageFormatter.AppendArgument("systemFolder", systemFolder);
+
+                if (systemFolder.PathEquals(folder))
+                {
+                    context.MessageFormatter.AppendArgument("relationship", "child of");
+
+                    return false;
+                }
+
+                if (systemFolder.IsParentPath(folder))
+                {
+                    context.MessageFormatter.AppendArgument("relationship", "child of");
+
+                    return false;
+                }
+            }
+            else
+            {
+                var folders = new[]
+                              {
+                                  "/bin",
+                                  "/boot",
+                                  "/lib",
+                                  "/sbin",
+                                  "/srv",
+                                  "/proc"
+                              };
+
+                foreach (var f in folders)
+                {
+                    context.MessageFormatter.AppendArgument("systemFolder", f);
+
+                    if (f.PathEquals(folder))
+                    {
+                        context.MessageFormatter.AppendArgument("relationship", "child of");
+
+                        return false;
+                    }
+
+                    if (f.IsParentPath(folder))
+                    {
+                        context.MessageFormatter.AppendArgument("relationship", "child of");
+
+                        return false;
+                    }
+                }
+            }
+
+            return true;
+        }
+    }
+}