How do I repair registry errors after a virus?

Hello, here is some background information about my issue. Yesterday my computer was infected with kag.exe also known as the XP Security 2011 Virus. It took control of my computer with the annoying popup anytime I tried to run anything like IE8, Firefox, Malwarebytes, the Run prompt, etc. I could get these things to work (except the MWB) by closing the popup that appeared after attempting to open and after ending the process 'kag.exe'. I was able to remove this virus in Safe Mode by entering 'msconfig' in Run and forcing a Safe Boot. However, my board is a Gigabyte GA-P35-DS3L and there are major issues with this board when trying to get into Safe Mode on a startup. I have never been able to hit F8 and get into the screen to select Safe Mode. Now, after the virus has been removed, when I boot into normal mode I cannot open anything that was previously taken control of by this virus. This includes IE8, Firefox, and Run. I am typing from this computer right now because I found a way to get online by clicking on the Dell Solution Center icon. This is where I need help from someone with more experience as I have no idea how to proceed to fix my system.

I tried using Run but it doesn't work. I tried downloading IE8 but it won't open and I get a message saying that rundll32.exe is damaged or corrupted. How can I repair this? I have a Windows XP SP1 CD but I cannot fix anything with this CD because I am running at least SP2 and it won't let me "update" to an older version or somthing like that. That is what I remember when trying to do something else two years ago and not what was said recently. Any help is appreciated as I need this computer for school.

At the very least I would like help being able to save files onto a CD/DVD so I can transfer them back to my computer if I format C: since I cannot do that at this moment.