Well everything was working fine for about a year but now when ever i try to join a gmod sever
it gets stuck on the sever loading screen and on task manager it says hl2.exe is not responding
if anyone could help that would be great.
Tab out of the game and don't tab back in on the loading screen, only tab back in when you see the game has loaded up fully. Usually when I tab out in the loading screen or click somewhere else on the screen it windows detects that Garrys mod isn't working then closes it, so just leave it and let it do it's thing. Or try re-installing like Alex said.