I just installed an HP Officejet 6480 on two different computers. Every time I reboot, on either computer, I get a window with c:\Program Files\HP. Now, this doesn't cause any problems, but it's certainly annoying, and I can't find anywhere in the HP settings that controls this, nor in msconfig, unless it the HP Digital Imaging Common Startup--but I'd think that would only start the HP Monitor itself.

Does anyone have any idea how to turn off this window popup on reboot?

Go to the HP website and do an online chat with their techs there. Very helpful. Had same thing happen with my printer and knew that one of the files was the culprit but was not certain which one. Went to their online Live Chat and it was solved in just a few minutes.