1) From www.HP.com I downloaded “HP All-In-One” software for my HP PSC 1510 Printer and then ran the install;
2) the finish screen came up; but also an error screen came up “The features you are trying to use is on a CD-Rom… Insert the “TrayApp” disk and click OK”
3) I did insert my original “HP All-In-One” software CD, but it still could not find "TrayApp.msi" So, the installation is incomplete.
4) If I try to run HP Solution Center, error message comes up: Parsing error in file
But, that's exactly what i tried to do "completely reinstall the software."
And followed the instructions @ Resolving MSI Startup Errors - HP Customer Care when the message appears that TrayApp cannot be found and original CD is needed, I inserted the CD. But, it still couldn't find TrayApp.
As far as the other option to find TrayApp via Browser, there is no TrayApp.msi file anywhere on my PC.
I installed the HP download (and update) a week or so ago and the install files are still on my machine. I installed it after reinstalling Vista, so I didn't have a previous version, though.
I found TrayApp.msi in the C:\Users\Ed\AppData\Local\Temp\7zS4941\setup\trayapp folder.
Given that I didn't have your problem, even if you find it there it may not work if there's a problem with your msi registry entries. In that case, I'd suggest running the 'Windows Installer Cleanup' utility, as described in the link in osholt's last message.