HP PrecisionScan highjacks other scanner software

XP pro is installed. All scanner software worked correctly until HP PrecisionScan Pro software installed.

After installing the HP software, none of my other scanner programs worked correctly. If I ran any the other scanner programs, they were routed to the HP software. I uninstalled the HP software and all of the other programs quit working and gave an error that they could no longer find the HP software.

I uninstalled all scanned software and reinstalled all except the HP. All of them still return the same errors that the HP software is missing.

PLEASE HELP !!