you only need qick time to view quick time movies. the image files most 2d apps will open. slow way to see if it is an app causing: run msconfig, turn off all user installed software except antivirus and firewall. reboot several times, see if it hangs. if no, add one at a time through msconfig the user installed apps until it starts hanging again. the last app added to start at boot is the culprit. if it does hang, then ir is a hardware issue, and you need to take it in to be tested with the burn-in suite.