"Ok, here is another fix that I believe will help those of you that are still having this hpqgpc01.exe problem. As I read this thread, most of you, if not all, have 64 bit systems. But you are probably running a 32 bit file system. So lets try this. Load your printer disc in your CD drive, then go to : START, CONTROL PANEL, PRINTER. Then right click on printer and go to properties. Go to SHARING. Click on CHANGE SHARING OPTIONS. Click CONTINUE. Go down to DRIVERS and click on ADDITIONAL DRIVERS. X64 is the 64 bit driver, but remember that you probably have the files loaded in your X86 file which is 32 bit . Leave the X64 file alone, but click the X86 file. Then close out the program. When you go back, the file should show both the X64 & X86 file as Type 3 User Mode INSTALLED-YES. When you power down the computer you will still see the hpqgpc01.exe file pop up because you will need to restart the computer for the change to take effect. But after that, you shouldn't see the error sign on your next shut down. Hope that helps. Let me know if it works for you.
Tom" from http://h30434.www3.hp.com/psg/board/message?board.id=Networking&thread.id=189
I have an HP m9400t purchased 12/08 loaded with Windows Vista Home Premium 64-bit. Whenever I shut down computer the above "subject" error pops up. After some four attempts following HP LIVE CHAT service, it dawned on me that obviously they have no clue. I entered the HP FORUM and discovered "many" suffering with this same problem and, as me, received no help from HP. Evidently HP is in their "Denial" mode because, judging by the many mail in HP FORUM, some of whom are in the expert class, (I'm a novice) no one seems to be receiving any fix to cure the problem. I'm very disappointed and lost.........any one have a cure? Thanks. Chuck