The darndest thing has happened. I had to uninstall FS 2004, the problem unrelated to FS 2004 (no easy task as it turns out) and while trying to re-install the program was met with the following message:invalid page fault in module fsui.dll.Microsoft Flight Simulator module performed an invalid memory access.I've tried re-installing 3 or 4 times but to no avail. I get the opening splash screen then the above noted messages. Naturally the program shuts down after each try. I've had the system cleaned up by Norton and find no problems with the basic system.The original installation was fine, with no defects.I'm at a loss to figure this out. I could sure use some help with this problem since I'm "grounded" until a solution is found.Jack

Did you completely remove _all_ files associated with the previous installation of FS9? If you only depended upon the uninstall to remove everything, that could be what's wrong....the new install sees something that was left-over and can't comprehend. The file that you quote resides in the Modules Folder. If you had added files to that folder, which are not part of FS default under the original install(like FSUIPC, e.g.), that folder's contents would not be fully emptied.

You could also change the name of the Microsoft Games directory before reinstalling FS9. This will preserve you're add ons to some extent, as opposed to deleting the directory. David

Barney.......Thanks for the reply.I checked, as best as possible, and did find some files still left. I deleted and re-installed, with the same problem showing up. Then I thought that masybe I'd try to install on my other hard drive, the same result. I'm beginning to think that there is a problem with one of the 4 disks.I've contacted MS help folks and they've sent me a 5 page list of things to try. It's complex enough to take a couple of days but I'll give it a whirl.Again thanks for the effort.Jack

I had a similar problem. The problem was a register entry. How I found out is I has a 2002 version of Norton Utilites, ran one of there advance checkers and guess what? Left over register entries. Remove them and all went well.