Vista SP2 was released on June 30th, and appears an an ‘Important Update’ in the Windows update list.

It is a dangerous update. SP2 updates some 50,000 files. If any one of them is corrupt, your computer may stall on restart.

Prior to running SP2, take the following steps:

1.  Back up your important files and settings.

2.  Go to Accessories in the Start menu, and open Command Prompt. Type in the following: sfc /scannow   then press enter.

There is a space between the c and the forward slash. This command will check the integrity of your Windows system files. Have your Vista install disk handy – you will need it if any of your files have to be repaired.

Once this is done, restart your computer, disable your antivirus software, and download and install SP2.

It should now run smoothly. The file update on restart takes some time, so be patient.

If you install SP2 and the computer stalls when it restarts, you will see a message consisting of a numerical code and a filename. The filename tells you the name of the file which is preventing the update from continuing.

If this happens, note the filename. Start the computer into DOS mode (you may need to boot to your Vista install disk, choose “Repair Your Computer’ then choose ‘Command Prompt’). Find the corrupt file (try windows/system32 first, unless you know where the file is). Change the file extension to .old.

For example, if the offending file is trouble.dll, you would type: ren trouble.dll trouble.old   and press enter.

Then restart the computer. Repeat this process till you work through any other corrupt system files.

Windows should then start normally.

You should not have this problem if you run sfc /scannow before installing the update.

Good luck!