If you are talking about the AMD Dual-Core Optimizer patch, that patch will not effect the game in the way you are suggesting it has, unless your computer has a virus, or something else messing with executables, or the installation of the patch was aborted by resetting the computer in the middle of the installation.
Thousands of people have installed the AMD dual-core optimizer patch without any adverse side-effects to any software. It is an absolute requirement for some software packages to run correctly.
More than likely a firewall is blocking the game's access to the Internet, if you cannot get passed the login.
Check the 'Add/Remove Programs' ICON, in the Control Panel, for a de-installer.