New Hard Disk after BSOD – How to repair original WinXP

I installed a new hd and winXP after BSOD (bad pool caller) and the original disk is now a second disk. All the data is there. Disk appears to be fine. Is there a way to repair the boot issues ( driver or whatever)from the new installation so I can boot off the original hard disk which has lots of software I don’t want to re-install again.