MAJOR XP Logon Problem!

Just cleaned about 12 viruses from a computer that's been sitting in my house for a little over a year. After fixing/deleting infected files, I had to repair my Windows installation. After repairing, my computer starts up and give me only one account at the logon screen: Guest. It asks for a password, but I've tried everything AND tried logging on with no password. It gives me a message along the lines of "Can't find/logon to that account." When I boot in safe mode, it gives me the guest account and Administrator account, but when I login with no password or "admin" on the Administrator account, I get the same message. There's no way I can get into Windows whatsoever.
I can't lose the files I have on my computer. I have old pictures and tax files I can't erase. Is there any way to fix this problem or perhaps bypass the logon screen completely? I have to stress again how important it is that I access these files, I can't restore the computer and I can't pay to have it fixed right now. Any help is GREATLY appreciated. Thanks..

 

I can't get into Windows to run anything though I've heard of repeating the repair operation and pressing Shift-F10 when it says "Installing Devices", then running from there in DOS. Can anyone verify this?

 

haha I understand, but no, it's legal. It's my dad's computer, he bought it about 2 years ago and I still have the original XP disc.

I just worked around the problem. After hours of searching the library and internet for an answer and talking to my local computer geeks, I just decided to install a second instance of XP under C:\Vindows. haha.. Since I was able to do it without reformatting, I still have the My Documents folder from my old user account, and everything I needed to back up is in there. Now I just need to backup, then reformat, so no worries!

Thank you much!