KenK wrote:
Anyone have any idea what the computer is doing so actively when you aren't
using it? I often see the activity light flickering but have no idea what
it's doing. Sometimes no light activity.

TIA

That's the defragmenter running, and moving around prefetch
files or something. If you move the mouse, or attempt to investigate,
the defragmenter will frequently exit so you can't see what it's doing.
It doesn't exit immediately - that activity light can stay illuminated
for 30 seconds or so, after you try to get into the OS.

You might watch it with ProcMon (Process Monitor, Sysinternals), if
you want to see what it's doing. At the time, that's what I used
to verify what sector addresses it was using.

The prefetch movement thing can get into a loop. I could hear
a slight "singing" noise coming from my previous hard drive,
and the defragmenter doing the file moves, was moving the
same sectors to the same place, a "local minima" in the algorithm.
Just moving some files around a bit, affects the maths enough
that it stops pounding on that item. The program did not realize
that reading from sector 1234 and writing the stuff back to
sector 1234, was pointless. And done at high speed, it makes
the drive "sing". Moving a few files around, is sufficient
to have it read from 1234 and write to 5678, and that breaks
the loop and eventually it will stop when it's "satisfied".

The company who wrote the WinXP defragmenter is "President Software"
or such. There might be some Wiki info on it. The defragmenter was
not written by Microsoft. Whereas I suspect Microsoft wrote the
defragmenter on the Vista+ ones, as the defragmenter is much more
practical and not a "showoff". The Vista+ versions focus on "performance"
and are not a beauty contest like a commercial defragmenter is.
That's why the Microsoft defragmenter finishes before a commercial
one would. No shoeshine. But back in the WinXP era, Microsoft
contracted that part out, so the result has commercial quality
behavior, including a prefetch shoeshine without you knowing
what is running. And that makes the LED come on.

Paul