I amended your post and put that long header into the body of the post.
That's XP Pro SP3 I hope.
However if you can't boot into it at all in any mode I'm not too sure what to suggest other than taking it to a PC repair shop as that sounds like hardware failure to me.
Does it have a recovery partition or a system CD/DVD that can be inserted to repair or even format and reinstall the system?
Is there any reason for you to suspect that this is an infection?
I'm thinking more on the lines of a general PC problem here and you may be best advised asking for help on a forum that specializes in such such as THESE guys whom I know pretty well.