Windows XP System Restore:
Windows XP System Restore is a backup tool that will help you restore you computer configuration to an earlier point without losing data.
This is ideal if your computer is not operating well because of a configuration change, a problem with an application, or the introduction of viruses or other unwanted software. By restoring to an earlier point—a point before your computer began displaying problems—you may be able to easily resolve the problems. (Note: Applications that have been installed since the restore point will be removed.)
Steps:
- Click on the Start \ Programs \ Accessories \ System Tools \ System Restore.
- In the Restore wizard screen, select ‘Restore my computer to an earlier time’ and click ‘Next.’

- From the calendar screen, choose a bolded date where there is an available restore point and then click a restore point in the right hand side.

- You'll get a confirmation screen asking if you to continue.

- Confirm to reboot and restore your computer back to the previous configuration.