after system repair - cursor aritifacts/screen mess

hello,

when I booted up my system today, I got the error that c:
\windows\system32\config\system was corrupted or missing.

Using the repair console I replaced this file with the file
from c:\windows\repair

After reinstalling all my drivers/protocols, all seems to
be running nicely again, except that I have a square block
with horizontal lines around my cursor, and some vertical
lines in some of the desktop icons.

If I tune down hardware acceleration one notch, the square
around the cursor disappear, but now the cursor leaves
artifacts on my screen. I've reinstalled SP1, directX and
my video-card drivers (several versions) but none seem to
fix the problem.

btw, if I reboot after uninstalling the video drivers, the
artifacts aren't there, but as soon as I install the
catalyst drivers for my ati radeon 9700 (versions 3.8, 3.9
and 3.10) it appears again.

Now I suspect that I have to reinstall a windows update,
but since I've installed them allready, I don't know which
one to install again....

Hope one of you can help me out

Sincerely,