Thanks, Eddy, David, mchain.
Ohhh, I see now ... Pentium 4 and above is avast compatible. Good to know. Cuz here and there I have seen this, I believe an Acer something or other desktop computer for sale at Walmart. Very cheap, but it has a Celeron something processor. So I'm guessing IF I would have bought that computer, avast wouldn't have worked on it.
Interesting that you mention checking the condition of the HD, mchain. At the beginning of the 1st System Recovery on that HP Pavilion, it prompted me if I wanted to run a Hardware Diagnostics. So I clicked to go ahead and run the basic test of everything. The RAM passed with flying colors. However, the 2nd step was to check the HD. As soon as it got to that category, I got the indication that the HD failed the Self Test or something along those lines. Since the computer was working and my brother had not informed me of any history of it being flaky, I just exited out of the diags and proceeded with the System Recovery. So who knows? Maybe there COULD be some intermittent issue with the HD.
I'm probably gonna give the HP Pavilion another shot sometime this weekend. It has PC Doctor in it, so I'll run those diags, especially the HD Test. I'll almost assuredly perform yet another System Recovery. However, this time, aside of immediately removing Norton ... I'll leave everything else (myriad of junk apps) intact temporarily. And I won't immediately install my various apps temporarily. I'll just get avast in there and my NetZero to connect to the Net. I'll then check to see how stable it is with minimum changes from factory default.
Little by little, step by step I'll remove and add apps and see if hopefully I can zero in on at what point and possibly with exactly what app the system becomes unstable.