If you're still unable to update Windows, here are three more things you can try: Check your clock to make sure your PC is set to the correct time and date.Double-click the time in the bottom-right corner of the screen to open the Date and Time Properties dialog box .Stop Windows from restarting automatically after a crash by unchecking Automatically restart in the Startup and Recovery Settings dialog box.This doesn't address the cause of the "crashes", however.Vista recommends a restore point; if you approve, click Next Next, make your selection, and step through the wizard.
Just be sure to reactivate your security programs before you browse anywhere else.
Log into another administrator account and try to update.
If you don't have two administrator accounts, open the User Accounts Control Panel applet, click Create a new account , and step through the wizard, choosing Computer administrator as the account type . To enter Safe Mode, press F8 after your PC starts but before Windows loads, and choose Safe Mode from the resulting menu.
Scan your Windows Update log file for clues to your system's update failures.
Now visit the Windows Update Troubleshooter and browse around for an entry relating to the error.