The toolset error could be caused by a referenced project. You can find the culprit by doing the following:
- Increase the build verbosity level to diagnostic: Tools > Options > Projects and Solutions > Build and Run > MSBuild project build output verbosity > Diagnostic
- Disable mulithreaded builds so log entries are sequential and thus easier to read: Tools > Options > Projects and Solutions > Build and Run > maximum number of parallel project builds > 1
- Build just the single project that is giving the build error: right click the project X in Solution Explorer > Project Only > Build Only X
- When the build finishes, locate the error in the output and look at the previous few lines to identify the referenced project causing the error
For example, if you are building project X you might get the following error showing that referenced project FooBar.vcxproj specifies the toolset as v110 causing the error:
Target "PlatformPrepareForBuild: (TargetId:114)" in file "C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\Platforms\x64\Microsoft.Cpp.x64.Targets" from project "D:\Foo\Bar\FooBar.vcxproj" (target "PrepareForBuild" depends on it):
Using "VCMessage" task from assembly "Microsoft.Build.CppTasks.Common, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03d5f8f12d50a3a".
Task "VCMessage" (TaskId:63)
C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\Platforms\x64\Microsoft.Cpp.x64.Targets(514,5): error MSB8008: Specified platform toolset (v110) is not installed or invalid. Please make sure that a supported PlatformToolset value is selected.
After resolving the problem, be sure to put back the build output verbosity to normal and revert any change to the number of parallel project builds.
<PlatformToolset>element set to "v100". And compare it with another .vcxproj file you created with VS2010. - Hans Passant