See this site:

http://www.windowsreinstall.com/

The site refers to a reinstall as a "Repair" (but see No. 3 below):

I would point out two things about a reinstallation:

1. Contrary to many concerns, a Reinstall DOES NOT change your computer except for replacing files with the original Windows installation files--your desktop and menus and Documents and Settings all stay the same. This may or may not have an effect on some installed programs--I have reinstalled many many times and it seems with XP, I've never had any problem

2. Reinstall is often an easy way to fix a nagging problem that there seems to be no solution to--you can do it easily in about a half hour with a minimum of effort as long as you have your original CD and product code AND you have bootable CD drive which most are--you can test it easily by changing the boot order to the CD and inserting your Windows CD to see if it starts booting. You can then just CTRL-ALT-DEL while its loading setup files and change the boot order back--Windows doesn't change anything until you go through few commands to tell it too. That's not to say that you should use this right away--a reinstall is the option to use when you've exhausted efforts to fix the specific problem.

3. DO NOT use the "Repair windows Through the Recovery Console" option--follow the instructions for your OS in the above link.

4. Here are quick Links to XP Reinstall Guides for all Service Packs:

Professional Editiion:

http://www.windowsxpprofessional.win...pair/part1.htm

Home Edition:

http://www.windowsxphome.windowsrein...pair/index.htm

Anyone else can feel free to add comments.