Hmm, maybe somebody else can figure that out. I would just throw up my hands and
start over. I have worked on PC software and hardware for many years and I do not
have the intellect to trace out everything without the aid of additional resources.
So I would try everything on another system until I find a pattern. Often the first
or second error you get is the clue and the rest is just trash. I did a Google on
'CleanPFR failed SP 4' and got lots of hits. Here is a good one: tomshardware.com
Installing SP4
Also, the microsoft.com has some articles on this problem.