How to reformat your computer *(urgent)*

I recently downloaded a program from sythe's runescape cheats and scanned. It came up clean on jotti, so tried it and it had an error. I left for an hour and when i come back, my runescape character got his bank swept and i think the program had a well hidden keylogger. I want to reformat my computer, if thats what its called to say like two days ago, but i dont have the cd. Is there anyway to do this?

 

Unfortunately, you can't if you don't have the CD. You can try and delete everything except the Windows files but the keylogger might be in System32...

 

Do you know where i could get the cd? And are you positive? Because i do a lot of online bill paying and stuff. I deleted the program and stuff, but i know that won't do anything