Hi ivnj, try this
Windows Update does not remember updatesOpen Control Panel/Add or Remove. See the list of installed Hot Fixes
Make a list of the Q***** numbers associated with each fix.
Open Windows Update/Scan for Updates
Make a second list with the Q***** numbers
Note each Q****** that appears on BOTH list.
Exit Windows Update. Start/run Regedit.
HKEY_LOCAL_MACHINESOFTWAREMICROSOFTUPDATESWINDOWSXPSP1
Right click on the SP1 folder and click export. Save it.
Double click on the SP1 folder and see a list of Q********
Locate the Q********* which were on BOTH of your list.
Delete these Q******** but only these. Do not delete them all.
Shutdown/Reboot