There is a known issue when you install the Team Build server on a machine that does not have Visual studio installed. You might encounter the following error in the build log when running a Unit test.
Run has the following issue(s):
Could not load file or assembly 'Microsoft.VisualStudio.Enterprise.ASPNetHelper, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.
This is caused by a missing Dll that is available if you run on a system that has visual Studio Installed.
To work around this issue do the following:
Copy the Microsoft.VisualStudio.Enterprise.AspNetHelper.dll from the D:\Program Files\Visual Studio 2005 Test Execution\LoadTest folder to the D:\Program Files\Microsoft Visual Studio 8\Common7\IDE\PrivateAssemblies folder.
After you made this manual adjustment to the server you will see the tests pass, but the warnings are still generated.
You can find more info on this now known issue here.