How to Force a System Restore if Windows Vista Won't Run
So something has gone terribly wrong with your system, and you want to get Windows back to the way it was a day ago (or, if you installed Uncle Billy Joe Bob’s Blaster Beta, maybe just a few seconds ago). If you've managed to fry the system so badly that Windows won't even start, you can use your function keys to force Windows Vista to run a system restore.
Reboot your computer.
Every PC goes through its self-test a little differently, but typically you see a counter as the PC tests its memory, followed by notices about keyboard and mouse drivers, and finally a notice about your hard drives (assuming that these don’t flash by so fast that you see only a blur).
Immediately after you see the message that your hard drive is alive, press F8 and hold it down.
Vista may show you the Windows Error Recovery screen or it may show you a similar screen, with more options, called Advanced Boot Options.
Use the down arrow to highlight Last Known Good Configuration (Advanced).
The Last Known Good Configuration choice simply runs Windows System Restore using the last restore point and then boots normally.
The computer should complete the restore and restart.
If you can’t get Windows to start, and the Last Known Good Configuration doesn’t work — or if you can’t even get to the Windows Error Recovery screen — it’s time to haul out the big guns. Follow the instructions on the screen shown in the Windows Error Recover Screen: Grab your Vista installation CD, restart your computer, choose your language, click Next, and then click the Repair Your Computer link. But try using the Last Known Good Configuration first, okay?
Some computer manufacturers build a recovery system into the computer. If this is the case on your computer, you won't need the Vista Installation CDs. When you click Repair Your Computer, the computer will simply access the recovery files and begin a recovery wizard.
Windows automatically makes a restore point when you restore — so if you run through these steps twice in a row (without setting a new restore point), the second time you use Last Known Good Configuration, you get your original (presumably bad!) restore point.