I have three suggestions:
It's well documented (i.e. a common problem) that WinXP is finicky and won't run on all hardware. Is your computer a "brand name" (like Dell, Compaq, eMachine, etc? Post the brand and model number, along with basic specs like how much RAM, processor type/speed and size of hard disk. If not a brand name, open the box (take anti-static precautions) and look for brand/model information on motherboard and note any brand/type information re BIOS, video card, hard drive, etc. Post this information (it takes longer to type this request than to get the info!)
Now, for the suggestions:
1) The problem is likely with your video card. Swap yours with a friend and try again. If that doesn't fix it, change your motherboard to an ASUS (absolutely never use Elitegroup Computer System motherboards!) and reinstall. One of those changes will fix it;
2) Get a copy of Windows 2000 (*not* Millenium Edition) and install that instead. WinXP is one of the worst releases for hardware incompatibility;
3) Download (free!) and install a Linux operating system like Kanotix. The installation is much better (and just as easy as) Windows and all software is free. For wordprocessing, use OpenOffice.org -- it reads/writes MS Office documents. It has built-in PDF creation (no need to purchase $600 Adobe Acrobat), built-in CD/DVD burning, etc etc. Linux is finally ready for us home users - "Forgeddaboudit"
http://kanotix.com/files/kanotix/mirrors.html
(get the Fix2 iso)