I'd start over since you just recently reinstalled the operating system. Sometimes it's easier than problem solving.
I reformatted useing the WINxp Home CD that came with the laptop. It did ask and I did format the HD, but now at start up it is asking which OS I want to boot from. The first choice is the new install I just did, the second choice (I believe) is the "majorly virusly corrupted" old version, which when clicked on gives a warnign message "you can't boot, it's corrupt". How do I get rid of the BAD OS option? he's a "click and play kinda person, I am trying to make it as simple as possible for him.
This is a college friends laptop, who had no idea how to keep it protected against the internet (good grief) so I am trying to reload it for him.