Quote: "Do you know what could of caused this?"
To be honest I'm not sure, I've had this problem (and noticed that others have too) on other demos.
Has it worked on anyone's PC other than your own? Maybe it's trying to reference files that I don't have

. Specs wise I'm running Windows XP SP2 on a AMD Athlon64 3200+ Venice, 1GB DDR400, 128MB GeForce 6600GT - so I don't think it's my specs

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You could try using something like Install Creator (
http://www.clickteam.com/English/install_creator.htm).
I'd suggest that if it is working on other PCs that don't have FPSC installed (I do, but not in the default directory) then you should start a new thread with a direct link to the demo and include a few screenshots in the post. That way you'll get more feedback about the demo and possibly an answer to your problems.
Sorry I couldn't be of any more help.
Cheers, Rich.
EDIT: Following up from the problems you were having with the demo (black screen) I just realised that the most likely problem is that if you are using custom media of any kind then the exe you uploaded wouldn’t work as the media is a separate entity, if you’re only using stock media then I’m a little confused as by putting the exe into the “My Games” folder it should run no problem.
Anyway, the most likely solution to whatever the problem is should be to use the Install Creator software you have, FPSPack Lite, or simply rar or zip the game files (not fogetting to include the exe and all media folders).
Hope this solves your problem, if you haven’t solved it yourself already

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