I use the Microsoft-provided vshadow.exe tool to script some backups, but I got an error when trying to run it on a Windows 7 x64 machine:
ERROR: COM call "m_pVssObject->InitializeForBackup()" failed. - Returned HRESULT = 0x80042302 - Error text: <Unknown error code> - Please re-run VSHADOW.EXE with the /tracing option to get more details
That error is obviously unexplanatory, but some investigation led me to deduce that you can’t run the 32-bit version of the tool on a 64-bit version of Windows. The fix is to download the Windows 7 SDK, install the “Developer tools” portion, and dig the 64-bit version of the tool out from %ProgramFiles%\Microsoft SDKs\Windows\v7.0\Bin\x64\vsstools\vshadow.exe.
If you were Googling that error code, I just saved you some time. You’re welcome.