I got a trojan from a key generator that my sister installed on my computer and now I can't reformat it... I have the Windows XP Pro CD. I've tried booting from the cd but it won't let me and I've also tried running it from Windows and when I click on Install a message pops up saying the setup cannot continue because the version I have on my computer is newer than the one on the CD and that if I choose to delete the newer version everything will be lost, etc. There's a continue button that is "blocked", and the only enabled ones are Cancel and Details. Basically, it won't allow me to re-install Windows XP. Is there any other way to reformat? What keys do I press to make it boot from the CD? Please help me!!
Oh, and I've tried System Restore as well, and it removed all my previous restore points!