The message does not imply to me that I should reinstall PS CS5,it is talking about an individual component and that sounds like something that can be installed separately or should be installed separately from the whole program.
However, if you think a complete reinstall of CS5 is required to fix it, perhaps that what needs to be done.
Being admin on the computer and installing the software in the Admin mode are different. When the disk is put in the drive do not install. Explore the disk and look for the .exe file, right click on that and choose run as Admin. This will give PS the correct permission levels to install with.
Also ensure no other Adobe product is running in the background during install (task manager).
Turn off any anti-virus. Sometimes anti-virus will block software from installing correctly.
Also before you run the software right click on the icon, choose properties, compatibility and check run as Admin. This will give PS full security rights.
No need to turn off UAC in Windows 7 during install.
There was no other adobe product running in the back ground. This is not a Win 7 machine but a Vista 64. This is not being installed from a disk but rather a download. Again, the error message does not read "reinstall Photoshop to correct issue, it does say to install "XMP Panel 3.0 STI as if that is a separate and distinct program that can be found and run.
The run as admin does clear the issue. I now also recall having issues with the adobe installer for CS3 Suite on another machine. Looks like there still might be issues wih that.
Well, it appears that while the error code is technically correct, it needs an
adobe translator to step in and tell the end user that the "install of PS might have failed" or what ever. As it stands, it is NOT clear from the outside ( a non Adobe team member) what that means.
Thanks for your input Chris.