How to Restore Windows XP Without a Disc

Using System Restore
1. Ensure that System Restore is enabled by clicking 'Start>Control Panel>Performance and Maintenance.' Select the 'System Restore' tab. Under 'Available Drives,' see if the drive you want to restore is being monitored. Ensure that the 'Turn off System Restore on All Drives' check box is not checked.
2. Select 'Start>All Programs>Accessories>System Tools>System Restore.' This will open the System Restore Wizard window. Select the check box next to 'Restore my computer to an earlier time.' Click 'Next.'
3. Click on a date on the calendar that is at least 1 day in the past. In the pane on the right, select a restore point from the list. Click 'Next.'
4. Save your work and close any programs you currently have running. Click 'Next' to shut down Windows and restore your computer to an earlier state.
Recovering Windows XP from a Hard-Drive Partition
5. Click 'Start>My Computer.' See if your computer has a valid recovery partition. This should appear as an auxiliary hard drive in 'My Computer,' even if you only have one hard drive. Back up any documents you have created onto CD or other removable media before continuing.
6. Shut down your computer. Disconnect all peripheral devices, such as your printer, scanner and speakers. Leave the monitor, mouse and keyboard connected. Consult your computer's manual to determine which function key to press to get into Windows Recovery. Turn on your computer and watch for the splash screen, which provides instructions on how to get into recovery mode. Press the recovery function key before the computer begins booting Windows.
7. Follow the onscreen instructions. Look for 'Windows repair' or 'non-destructive recovery' to leave your user files on the hard drive. Select the option to format your hard drive if you have been experiencing severe errors in Windows XP, or if your operating system fails to boot.