I recently installed a Canon MX860 multi-function printer and it's software package, including the app that controls the scanning function. That app, Navigator EX 2.1, won't open. It returns an error message saying the program has encountered an error (unspecified) and will let me know when Windows determines what it is. An older version of the software for an older printer worked fine. On the advice of Canon, I installed the software under a different user account and it worked fine. I've cleaned the registry of all mentions of the older program and have also run Registry Booster to correct errors. I've uninstalled and reinstalled the printer and the software several times. Why would a program work under one user account and not another? Both were set up as administrators. Any suggestions much appreciated. Running Windows 7 32 bit Home Premium on an HP quad core with 3 GB RAM.