The Windows Vista System Restore feature will make sure that software installations, drivers, and other updates can be rolled back. The only price to this feature is some disk usage. If you want to disable System restore, which is a bad idea, it's really pretty simple.
Just to make sure you understand… Windows Vista has just been released. There are bugs. Things will crash. Disabling System Restore will keep you from rolling back changes.
So, you've read this far. Now let's disable it. Type system into the start menu search box, and pick the 4th item down, just labeled "System". (You could also right-click the computer icon and choose properties).
Now click the System protection link:
You'll see the checkboxes next to your different disks:
Once you uncheck the drive, click the "Turn System Restore Off" button.
Now you've got system restore disabled.