Try downloading the unofficial community 1.03 patch from CNCNZ.
I have had this error and have found the fix for windows 7 at least
Is is a problem accesing a DLL file that was previously open and now is restricted on windows 7
go to "control panel"
go to "user accounts"
Go to "User account settings" near the bottom of the list
set the slider you see to the lowest level then restart your PC
what you just altered is the level of security for windows files, now the dll's that where protected are free for the game to access, but be careful as it means that the files are open to any viruses you may encounter on the web so be very careful
now i must go. As I, for one, Welcome our new Psionic Overlord
I tried your solution, but it did not work - Windows 7
Right click, then click on "RUN AS AN ADMINISTRATOR". That should do the trick.
