2 Screens setup not working after update

Hi

I have a system running winXPpro sp1 with a two screen setup on two
different Craphicadapter. I did some Winupdates (not the SP2 one!) after the
reboot only onw screen was working. I did try to set it back to the two
screens but did not work. This are the error messages:

You can't change the display settings as you don't have sufficient rights
(I'm logged in as adminsitrator).

After this message there is another one. You can't use the installed graphic
drivers as they have been written for an older Windows version and are not
compatible with the current one. The standard Windows VGA driver has been set
up.

I did than download the latest drivers from ASUS and Matrox installed it but
still get the same error message.

Is there any solution for this?

Any help appreciated