McAfee gateway is a system service created on a system tha's giving you internet. As far as I know there's no NEED to have it on a desktop, since it's just a content filtering application, and if you DID remove it then I'm not sure what to tell you as that goes beyond my interactions with it.
The only reason I know anything of it at all is because the hospital that my wife works at uses it, and finding a way to bypass it for software has even until this point been a bitch.
The only luck I had was using a VPN server created on my home desktop, and dialing into it from the laptop at the hospital.
So as to how to fix your internet issues created from deleting anything Idunno what to tell you, because there's no reason that uninstalling antivirus should prevent you from having net.
