How does System restore work?
Windows XP periodically records a snapshot of a part of your computer. These snapshots are called restore points. Windows XP also creates restore points at the time of significant system events (such as when an application or driver is installed) or you can create and name your own restore points at any time. If you’ve installed a program that has made your computer unstable, you can open system restore, choose a restore point and return your computer to it’s previous stable state. When you run System Restore, a calendar is displayed to help you find restore points. If you don’t use your computer every day, some days might not have any restore points. If you use your computer frequently, you might have restore points almost every day and some days might have several restore points. Please note that System Restore does not magically restore your entire system to a previous state. It only reverts some important parts of your system. Therefore it is highly recommended to first uninstall t