United Offensive installation

[reddragon105]

if the original is indeed installed correctly on your PC then the expansion pack should install. if it has trouble detecting the original, then perhaps it is checking the registry and the entry is not correct (i had a registry problem with installing MOHAA expansion packs that caused them to not acknowledge the original was there). or perhaps you have installed the original in a folder other that the default directory and it is looking in the wrong place.

either way, the best way to fix it would be to reinstall the original. which would require you to buy the game again

of course, as Call of Duty is a system requirement for United Offensive, you should really have the original to be playing the expansion anyway, as selling the game but leaving it on your PC is effectively making a copy of/stealing it