Backup data by removing the hard disk and connecting to another computer.

Another possibility is opening up your PC and taking out the hard disk and connect it with a ATA to USB converter on another PC.

An advantage of opening your PC, is that you will have the opportunity to inspect and vacuum clean the pc. This is very important for the cooling fans, especially the CPU fan. The inside of a computer can get extremely dusty even after only one year. If you clean out the dust from the CPU fan, it will be less likely fail due to overheating. Also the fan will have to make fewer rounds per minute so your PC might actually become quieter. (only if your motherboard has a BIOS that supports temperature dependent fan speed control, for example Qfan on Asus motherboards.)

Another advantage of connecting the hard disk to another computer is that you will be able to easily scan the data for viruses before you backup the data. Also check the drive’s integrity. You will be able to copy the data, format the disk and then copy the data back into a folder so you won’t have to copy the data after you reinstalled windows. Just make sure when you do this, you do not format the disk during the windows install because otherwise you will have to copy the data once again after the reinstall is completed.

Here is an example of such an ATA to USB converter, you can connect any hard disk on it, whether it is a small hard disk from a portable, a bigger hard disk from a PC, an older IDE or a newer SATA hard disk, this connector can do it all.

If you do not have a ATA to USB converter, you might as well use a hard disk enclosure to connect the hard disk to another PC, however you will have to check if the connectors inside of the enclosure you have, match the connectors on the hard disk you want to backup.

First disconnect any power to the pc, next open the PC by unscrewing the side panels. Next locate the hard drive and disconnect the power and data cable. Unscrew the hard disk screws. Connect it to your universal connector and then plug it into your PC. You are now ready to scan your data for viruses, check if your hard disk is working 100% and backup your data.

For a laptop it is very similar, this is the procedure for taking out a hard disk out of a laptop and connect in enclosure: http://iamrainbow.wordpress.com/2007/07/24/data-recovery-from-notebooks-...

Instead of just copying the data, you might want to consider using the backup utility in Windows XP http://support.microsoft.com/kb/320820/