Connecting infected HD to computer?

We have several computers that are seriously infected, some to the point they are inoperable. I thought I would pull the hard drives out and put them in as slaves one at a time on another computer. Mainly to try to retrieve some of the data off the drives, disinfect them or at the last reformat them. I thought I would completely wipe out the computer and install XP fresh and before I connected an infected drive I would clone the C drive to a second drive. After trying to Cleanse the infected drive I would I would swap out the C drive with the clone and reformat the original and then clone back onto it the OP system and Malware programs and such and swap it back. Keep doing this for each infected drive so as to not cross infect the infected drives. Using Norton Ghost or some other program. I have Ghost 10 already but if there is a better program I would use it. Does this sound completely like a waste of time or might there be some advantage in doing this? Or maybe you have a better approach?