Garrys mod problem

Ok I bought Garry’s mod and only really used single player until my bud bought it yesterday. We planned on playing multiplayer but everytime i join a server, i can play for 10 seconds, then gmod crashes with no error, i just shutdowns and places me on my desktop. This also happens with all my other steam games on multiplayer. Any ideas?

System Specs

PNY nForce 630i GeForce 7150 Socket 775 Motherboard
2.2GHZ Intel Pentium dual core CPU
4GB DDR2 677 mHZ RAM
nVidia Geforce 9600 GSO video card

try adding -windowed into startup options in steam.

I tried that, still crashes. Before it crashes the screen in game slowly turns pitch white. I updated my video drivers to see if that solved it but it didn’t.

Its not the video card, as i have the same one as that, and mine works fine on gmod. But a video card would not casue this…

Hmmmmm

Post temps.
http://www.cpuid.com/download/hwmonitor/HWMonitor_114_setup.exe

I believe its a network issue or a firewall issue, are there any ports I should manually forward? I have AVG

Can anyone help please?

A firewall problem would not crash you.

Then it must be a network issue, any suggestions? Could it be any to do with my router? Any port settings that need to be made?