Tracker.exe
这个进程存在导致不能删除目录.
Tracker.exe is required to correctly incrementally generate resources in some circumstances,
such as when building on a 64-bit OS using 32-bit MSBuild. This build requires Tracker.exe, but it could not be found.
The task is looking for Tracker.exe beneath the InstallationFolder value of the registry key
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SDKs\Windows\v7.0A.
http://stackoverflow.com/questions/13422178/visual-studio-2012-required-file-tracker-exe-is-missing