HAL.dll (I think) refers to the hardware abstraction layer. If you've redone the partition and reformatted, the only way you could get a virus back is if your bakcups (you made backups, right?) had infected files on in.
I'm having a little trouble following this. As I understand it, you put the 2nd driver (slave) with Win 98, and your master (XP), got corrupted. It almost sounds like your system tried to put Win 98 files on your XP boot sector (? doesn't really make sense, but please straighten me out..;)
If you've deleted the partition, and reformatted with the install disk, it should boot up just fine, once the OS is loaded. Back in the old days, you could use the 2nd copy of the sector tables (or whatever they're called nowadays, this is FAT stuff) by using the DOS command fdisk /mbr.
If you have another working computer around, you might peruse the Web for a Hard Disk diagnostic utility. Dell used to make one for authorized techs, but I'm sure the vendor who made the hard drive would have one as well. I've known hard drives not to 'travel well' from one system to another, and fail upon putting in a 'new' system.
Failing that, have you tried putting the Win 98 drive back in the old system? just a thought. We'll help, but we may need more info to find out what you've got going.

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)