CSRSS / Registry / Kernel times

Hi,

After upgrading to a new motherboard and processor last Friday, I found that Windows wouldn't boot and so did a 'repair' from the installation CD. This effectively downgraded me back to the original XP so I have since also re-installed SP2 and SP3, and allowed Windows Update to install all the recommended updates.

My system is now basically working, but is very sluggish (also, Windows Media Player won't start). I've determined that, even when nothing is running and Task Manager shows 99% System Idle Task, I still have 80 - 90% kernel times.

The Sysinternals Process Manager shows that the problem appears to be in the CSRSS and LSASS modules - they are repeatedly (approx 20 times per second) attempting to access the registry.

CSRSS in particular is constantly trying to access non-existent registry keys named:

HKLM\Software\Policies\Microsoft\Windows\Control Panel\Desktop
HKU\.Default\Software\Policies\Microsoft\Windows\Control Panel\Desktop

Although I know (from Google searches) that such keys do exist on some systems, they don't on mine, which seems to be the root of the problem. My system instead has:

HKEY_USERS\.DEFAULT\Control Panel\Desktop

Has my convoluted downgrade / upgrade path left Windows confused about what registry keys it should be looking for? Do different versions / service packs store the Desktop keys in different locations?

I read that the issue might be related to a corrupt user profile, but I tried creating a new user, and that user has the same problem.

I also know that CSRSS is often implicated in malware or virus infections, but I'm confident that that's not the case here - the problem is 99% certainly due to the upgrade.

My system is now running on an ECS GS7610 Ultra motherboard with AMD Athlon 64 3200+ processor, 1Gb RAM. Before the upgrade, it was an ASUS A7V333 with AMD XP2100, 1Gb RAM. Some example Process Monitor messages are included below.

I guess a reformat and reinstall would cure the problem, but any suggestions short of that would be welcome - thanks.

Chris.