Slaving laptop to desktop

I want to slave my laptop to my desktop so I can check the desktop for viruses, malware, etc.

The desktop is in big trouble, even turning itself on at night. Wha? Yep. I ran AVG before everything stopped responding and it found 6 different Trojans! I'm assuming they've been cleaned off by AVG, but the desktop is still sick.

I want to slave my laptop so I can run all the Virus/Spyware/Malware programs. At this point I'm thinking the desktop is dying so I'm looking at this as a learning experience about slaving computers too.

Desktop is
Dell 4300 running Windows XP

Laptop is Dell Inspiron 1503 running VISTA

What do I need to buy? Where do I connect? Thanks a bunch in advance.

Daugust