Windows actually has a builtin file hash function: in powershell, use Get-FileHash [filename] for a sha256 hash, and add the optional -Algorithm switch (-Algorithm MD5, for example) for other algorithms.

If you happen to be using Win8 in particular, stick with the powershell commandlet. Trying to find a windows file hash generator and then get Windows to actually run it will just make you unhappy. Screw you too, AppLocker.