How to Reinstall Windows XP without losing any data

Hello,
It has been almost a year since I have formatted my pc. But I dont want to fully format the drive also, so is there any way that I can reinstall Windows XP without losing any data? Thank you

If you must reinstall Windows XP while keeping your configuration and all applications you have already installed, it is possible. Under Windows XP, you put in the folder containing the Windows installation files (this may be the CD-ROM).
Run the command WINNT32 / unattend. Windows files then repair defective retaining your configuration and software. Useful if you do not want to reinstall it.

Over time, Windows loses stability. If you keep a computer for more than two years, at some point you're going to have to bite the bullet and reinstall Windows from scratch. But contrary to popular belief, you won't have to reformat your hard drive (with one exception, discussed below). The bad stuff you need to get rid of is all in your Windows folder.

Before you begin, gather your Windows and application CD-ROMs. Back up your data files (just to be safe), and then clear two days off your calendar. If everything goes smoothly, you can reinstall Windows in a few hours. But you have to assume something will go wrong: You may not be able to find a necessary CD, or data won't be where you thought it was, or something will simply refuse to work.

There's a difference between a repair reinstall and a complete reinstall. Though a repair (also called a refresh) will let you keep your current settings, a complete reinstall will give you a truly fresh version of Windows. Repairs are fast and easy, but they don't fix anywhere near as many problems. The instructions below are for total reinstalls, except where noted.

Your Vendor's Restore CD
Most computers ship with a vendor-specific restore CD rather than with a Microsoft Windows CD-ROM. (If your PC came with a Microsoft Windows CD, or if you bought a retail copy of Windows, skip to the section for your version.)

Some restore CDs give you all the options of a full Microsoft Windows CD, but with better instructions and the convenience of having all the right hardware drivers. Others can do nothing except reformat your hard drive and restore it to the condition it was in when you bought the PC. (This case is the exception I mentioned above that requires a reformat.)

If your restore CD is reformat-only, back up your data files to a network or a removable medium before reinstalling Windows. If you use Windows 98 or Me, back up C:\My Documents, plus the folders inside C:\Windows discussed in the 98/Me section below. If you have Windows 2000 or XP, back up C:\Documents and Settings. Also back up any other folders in which you store your data files.

For more information go to this link.