I need help using a recovery disk

So a couple days ago my computer took a painfully long time to get to the desktop. And now it doesn't even make it that far.
I keep getting this message that says, "Windows did not start successfully..." and it gives me options to start in safe mood, but I can't select them using the arrow keys. And I know my keyboard works.
So I want to wipe out everything on my computer because it's most likely a virus it can't recover from, and I have the disk to do it.
I have a Medion Windows XP computer, and I put the recovery disk in and it gives me that message like "Press any key to boot from CD..." and I do. But then it takes me right back to that "Windows did not start successfully" page.
I've tried pressing F8 and DEL before the computer boots up, but it doesn't take me to safe mood. I've tried everything I can think of and nothing seems to work.
How do I get my recovery CD to cooperate?
Please help! I really want to fix my computer.
Thank you.