The best course of action would be a quick restore of the program. Make certain no virus scanners are running currently. If you installed from a CD or download, make certain you have a copy of the install file to reinstall from. Begin by uninstalling the program. After the uninstall, make certain you check the install directory for any remaining files or folders:
C:\Program Files\Avanquest
or
C:\Program Files\VCOM\ (the default installation directory).
Delete any files and folders that you find. Once you have done this, proceed with the reinstall of the software.
If you are unable to use Add or Remove Programs to uninstall, please see this link for assistance.
http://support.microsoft.com/default.aspx?scid=kb;en-us;290301