Actually I dont have EA installed and have not have since being a Beta Tester as the betas would not run either while it was installed.
I have removed any reference I could find to any previous installation and the installations themselves and reinstalled V1 and still get the same problem.
MP runs or more correctly does not run as Single player game.
When installing V1 as a clean install I do not get asked to provide a user name or serial number which is rather strange - presumably FPSC is using a registration entry from EA which I cant see or remove.
I am not about to either fiddle in the registry of do a hard disk reformat on a system that has hundreds of thousands of files many of which are of importance belonging to important work I do for customers being a designer - for the sake of getting MP to work. It would take a weeks work finding and backing up to everything to many, many DVD's - hundreds of thousands of files.
Thats actually ridiculous though I know some have had to do a reformat. Not sure that would fix the problem anyway so its just not worth it.
A professional product should itself be designed by the makers to update any registry information as appropriate on installation and if FPSC does not do so then that needs correcting by TGC.