Can I download a virus from GamersGate?
Unless the publisher themselves wants to infect your PC with some Hacks.exe - no.
As an official distributor, we recieve all of our files directly from the publishers, so there is no chance of any malware being hidden in the game files. Some security software may ring a false positive alarm though. If that happen, simply deactivate the security software for the duration of the installation and then turn it back on.
P.S. For BitDefender you may turn off real time protection.