One of the problems that has come up several times in the forums is this: you turn on your PC and an installation program starts up and asks for a file called trayapp.msi - but it can't find the file no matter what you do. So you have to cancel out of the installation program. Every time you restart Windows, the same box comes up, and it is quite annoying!
This problem is related to the HP Imaging software that came with an HP product. It might be a scanner, printer, camera, or a multi-function printer. Sometimes the software gets screwed up so that it asks for this photogallery.msi file.
One fix that has been discovered for this problem is to place the CD that came with your HP product into the CD-ROM drive before you turn on your PC. When you turn it on, and Windows starts up, the installation program should recognize the CD and automatically find the trayapp.msi file, and the problem will be solved.
If it does not find it automatically, navigate to the folder on the CD called TrayApp. There, you will find the elusive TrayApp.msi file. Click on that, hit OK and the Imaging Monitor should extract the trayapp automatically. One reader has told us that he found the file on the CD in \Setup\trayapp\trayapp.msi
If this doesn't work, we recommend that you visit HP's support web site and download the latest drivers and imaging software for your product. Then, proceed to uninstall your HP software, reboot, and reinstall it using the files you downloaded.
Another user has reported that "the problem disappears when HP ImageZone (mine was v. 3.5) is uninstalled. Then, a "Minimal" installation of the HP printer software (mine was a Photosmart 8450) will run without causing the problem.