Quite a while ago the last online game in Generals? This is 7 or 8 years ago that EA switched off its servers for the game. Alternatives to play online are available. What seems to work best is GameRanger.
Of course, GenTool is now also an integral part of the installation to be able to play in an appropriate resolution. So you can play reasonably on modern computers. And also online. You may have to dig around a bit until you have everything for the installation. Game updates and No CD Patch should not be missing either. So here are the links for it supplied by GenTool.net:
Official Game Patches: www.gentool.net/download/patches/
No CD, No Mismatch executables: www.gentool.net/download/executables/