I will either reinstall the OS or clean the computer depending on a few variables.

1. If the computer is so infected it will barely run I'll either fix it to see how well I can get it running, and how much damage these malwares have actually done to the operating system.

Now if the client is extremely annoying I will have already informed them that there is no guarantee of whether or not this will work, sometimes doing both processes (the incident of the client paying enough to buy a new computer)

2. If the Clients PC has less than 2000 incidents from a Spysweeper scan, (or 750-900 from Spybot) I'll often clean the computer.

3. If the client informs me that there is no useful data, I will instantly GDisk it on the spot, and rebuild it.

4. If the computer is a PoS I'll often inform my clients to buy a new computer, and will transfer the data for them.

I like the challenge of cleaning extremely infected computers, and have seen some extremely bad ones, hundres of viruses and over 50000 hits on spyware scans, (multiple scans from a variety of programs) Hijackthis scans that span over 10-15 pages.

Now if its my personal machine, or a mission critical client system, you'd better believe I have 3 ghost images, with 2 of them offsite and will reimage them (after checking to see if I need to restore any data).

All-in-all I believe that its near impossible to fix a computer back to new standards if its been infected by viri, though Spyware you can often get back up and running.

and since I've seen the last few posts...

2 Odd Tools I always have on hand...

Hammer: useful for "fixing" certain annoying problems.
Drill: Might as well drill the dead hard drives.
Of course both of these strike fear in office managers around the world
*Grins Wickedly*