I will be doomed. PLEASE HELP ME.?

my computer was doing ok. I had a problem with internet explorer so I decided to re-install windows XP SP2, I putted in the cd and I started installing within windows, after getting the setup key the computer restarted and it came to the setup console, it showed the remaining time in which setupo will be completed, but everytime it comes to the "34 minute remaining" it stops. there is no problem with my installation cd. I don't knwo waht to do. I can't format my hard, since my doents folder has very important information. my C: drive in NFTS format and "my doents" folder is prtotected. How can I get rid of this installation. I don't want it at ll. I want to be able to log on to my previous installation but no matter what I try this setup screen comes up. Please help me. Thankyou