I would suggest checking to see if harddrive access is still running in
DMA mode. (Device manager, IDE controller, R-click on Primary Channel,
select Properties, then Advanced setting) Is it running DMA or POI?

Penang wrote:
Even on cold boot it takes more than 5 minutes for XP to get
everything back in shape, ready to be used.

I have tried everything, from defragmenting the HD to "cleaning" the
registry to even defragmenting the registry, and it's STILL so slow.

Software wise, I don't use too many. Just the typical office thingy,
that's all.

What else should I do to speed up my XP machine --- a 4-core CPU with
4GB of RAM ?