If you try an "upgrade" it will tell you that you already have a later (smarter) version then is on the install disk!
For at least a partial data level of safty if there is enough room on your hard drive to create another 50 gig partition, then copy all the stuff you dont want to lose onto it!
Then you could wipeout C:Drive and do a Clean install, and you still have that DATA onthe other partition!
I take it you have already did multiple cleanings (Viruses, spy's and Hijacker, Malware etc...)and edited msconfig? To try to bring the software back up to speed!
And saving the programs is another pain, I take it you dont have all the install disks! What type of programs are you talking about?
I take it you dont have an extra 60 gig sitting around anywhere!