Short answer: Yes.
Longer answser: You'll need to plug the drive into either the second plug on the new PC's HD cable (if it has the second plug otherwise you could also unplug the optical drive & use its lead into the old drive)
You might need to use disk formatting software to remove the boot flag on the old drive's Win98 partition. Not sure if WinXP will have a hissy fit with two HD, each with a boot flag. Win98 did. I use Ranish Partition Manager. Very good but use it carefully.