If you try to use the System File Checker tool in these scenarios, the command does not work as expected. If you try to repair Windows Vista in these scenarios, the System File Checker tool tries to repair the image. But the repair is not finished, and you receive a message that resembles the following:
C:\Users\User_Name>sfc /verifyonly /offwindir=c:\mount2\windows /offbootdir=c: Beginning system scan. This process will take some time. There is a system repair pending which requires reboot to complete. RestartWindows and run sfc again.
However, the repair process does not finish when you restart Windows Vista, and the image is not changed.