Vista SP1 crash after starting webcam

I have an Asus Z53 Jc that was working fine until I install the SP1 from
Vista... now everytime the webcam starts (nomatter what program) windows
crashes down... I've tried to reinstall the manufacter drives (they are no
longer recognized and do not install), automatic updates from microsoft, I've
used the restore funcion to a date previous to the problem but it is still
ctashing. Everything else is working except the webcam.
Can someone pleaseeeeeeeeeeeeeeeee help me?