I started having problems with this game after the 1.04 patch, so I decided to uninstall and go back to the 1.02, but the uninstall will not work. It says a problem occured with setup.exe and was terminating. But the install program would not let me install it again unless I uninstalled the game. So I just deleted everthing I could find related to psychonauts, and now the install program is still saying that 1.04 is installed. How can I get this thing to not see the program installed on here.

Deleting files manually is generally the worst thing that you can do when trying to uninstall a program, as there will still be no end of registry entries remaining which you can't really safely delete unless you know what you're doing. Those registry entries are what will be making the game think it's still installed.

If you can, reverse the deletion by restoring them from your recycle bin. Then, try to look for an uninstall program within the Psychonauts directory itself. If you can't, try going to add/remove programs in Windows' control panel to see if there's anything there related to Psychonauts.

If the files are gone for good, go to add/remove programs anyway. Sometimes Windows will let you automatically delete registry entries if it cannot find the original files, although this is not guaranteed to work. If it doesn't, the only real final route I can recommend is to post on the official Majesco support forum (http://majescoentertainment.com/vbulletin/forumdisplay.php?forumid=61).

yeah, I tried all that, but no matter where I tried to uninstall from, the auto start on the disk, or add/remove programs, it did the same thing. Thanks for trying anyway!

Try a registry cleaner, you can download these for free from load of places and they're generally helpful if you've done what you've done abd need to clean the registry so there's no more trace of the game. I can't think of any right now because I don't use them, but a simply google search should bring something up for you.