Thanks for your reply
I have a old PC, built on a ASUS P5QL-EM MB
Win XP have been acting up lately, with the symptom being a temporary freeze.
I installed Win7 on a partition of the same drive, and the problem was the same.
As I suspected a hard drive issue, I installed a new hard drive on that machine, and Win7 on that drive... and the problem still exists!
Using System Monitor, I notice the Activity stays at 100% for several minutes while nothing happens at all, same problem I have seen in many posts all over the web but never a definitive solution.
I'm NOT using Windows 8
I'll check your link right now.