Cleanup slave drive taken from old machine

Hi all!

Need some advice on my slave drive in Dell Dimension 3000, 2.6Gb P4, Win XP-Pro on both drives. Slave came out of my Dell that crashed and has lots of good data & files archived. Got most of the programs transferred to new Master.

Never did find out if I had malware or infection, or if it was hardware or a software glitch. Right at time of problems I lost all serial ports/USB ports and discovered 125 pages of startup programs! Most were Win NT, Office, C++ & KB stuff, with a second copy of each! Not even sure where they came from.

Thought it best to remove junk before going in and searching for malware? The fella I got newer machine from, who also installed my old drive as slave, said I'm safe because malware [if I have any] would not migrate from drive to drive, but I'm not convinved. So the plan is dump the junk and go for the malware, then use that drive for storage & backup.

I assume I should leave the OS on it. I'd like to know what's the absolute minimum needed in startup on slave, and how best to delete unwanted stuff, especially startup files?

No desire to reformat and reinstall OS because I think I only have the OEM XP-Pro disc from the older machine and that slave drive.

Thanks for any suggestions!