ErnisD: When I download something via gog, I can't do anything. Can't even open google. When I download something via steam it's download at more than 2mb per second, I can stream a live game from twitch and browse various websites. Why is that?
First thing: contact GOG support.
Are you using the GOG downloader client, or direct browser download? Also the subject title suggests you are complaining about slow download speed (from GOG?), so what kind of download speed do you get, and what should you be getting?
I am writing this while downloading The Witcher 2 from GOG with the downloader client, no problem. I also went to some online news sites, they come up fine. The game is downloading at around 1.2 Mbytes/s which I think is the max of my ADSL line anyway. At work I've downloaded with far higher speeds as well without issues.
If you are using the GOG downloader, have you tried to restrict the download speed a bit? This shouldn't be necessary, but maybe in your case you need to manually leave some download bandwidth to rest of your system?
If you are using direct browser downloads for your GOG games, are you using some fancy browser download manager or something, that could affect the downloads?
Not sure if some third-party firewall software could affect it too.
trentonlf: I ran into the same thing. Have a feeling it's just a sign of traffic from it being last day of sale so the servers are probably extra busy
I'm unsure if he was complaining about slow download speeds from GOG, or that when he is downloading something from GOG, he can't use the net connection for anything else in the meantime. I presume it is the latter, and for that the stress level of GOG servers shouldn't matter, I believe.