Mission Critical hell of a mess!!!!!!

Have a PC on the bench.Ath700, irongate chipset. This system has been through all the upgrades 3.11, win95, win95osr2, win98. 20gig HD. Has massive explorer errors, will not start in safe mode. No matter what program you open either the program you open will error out or explorer will error out. Cant access the reg as it will errorout and shut down. Can access ms config but cant apply any changes. I can't fdisk or format cause the damn thing will not allow saving of files anywhere. Cant reload win98 as I cant access the reg to get his code and he cant find his original disk. wont let me install from our OEM setup. Need to save the files as they have 5 years of Tax stuff. Seems like a virus and have ran F-prot and Innoculate and found nada. any ideas how I may restore this mess?

GHOST the drive. Reinstall a fresh copy of windows to a new drive (including a good Anti-Virus package and latest definitions)and then copy the important data to the new drive. View the registry files (system.dat & user.dat) in notepad from the old drive, make a note of his product id, then format the old drive.

I would just pop down to dos, load system.dat with edit and do a search for 'productkey'. Although after that many upgrades it is going to need a new install of windows if you want any hopes of stablity. Then reinstall all the apps and copy over your data files.

I would take out original drive, install another, load windows onto that, then install original drive as Slave and copy over tax stuff to "new" drive. Then after you make sure everything is ok on "new" drive, you can go back and drive copy to original drive.

Thanks to all who responded. I ended up using Ghost and partition magic to get the job done. How he managed to get 7 different virus I will never know. I had tried to use another drive as master with a fresh load of win98 and a fresh anti-virus with new definitions but it would not allow the scan. Ended up using NT4 to delete suspect files until I could run a full virus scan. Anyway got the job done, Customer is happy although $300.00 poorer. He now understands the value of a good anti-virus updated frequently. Thanks again Guys