Help! -random computer problem!

[cococomics]

Hi everyone, I'm having an emergency with my computer right now.
First off, I'm using Windows XP pro.
Last night when I got home I tried to start it up and it seemed to be working but then the screen came up that says "blah blah blah.. safe mode, safe mode with networking, safe mode with command prompt, last known good configuration, start windows normally".
Desperate, I tried all of these methods and one of two things happened. Either it restarted completely, or just came back to that screen.
There is a lot of stuff on my hard drive I can't afford to lose, and was dumb enough not to back up.
There was no hint that this problem was coming, it just happened out of the blue.
If there is a way to fix this without losing my data, please let me know! I am very desperate to get it working again!

Thank you!!!

[AvailNetworks]

have you installed or removed anything lately or taken on a windows update?

[DavidsAwesome]

usually "Start Windows Normally" works just fine.

If nothing works, you need to get it looked at.

[cococomics]

No, I haven't installed or removed anything or updated recently. Nothing out of the ordinary, this problem seems completely unprovoked! If possible I'd like to find out how to fix it myself. I think if I knew how I could definately fix it myself, and plus I don't have enough extra money right now to pay someone.

[cococomics]

Hi I fixed the problem myself! I just needed the XP disc, and I followed the instructions here:
http://www.webtree.ca/windowsxp/repair_xp.htm
to replace the NTLDR and NTDETECT.COM files and repair the boot sector and now my computer works again!