
Below are some feasible solutions and you can work your way down the list until the problem is fixed effectively. What can you do if your GMod keeps crashing? Don’t stress. Although the game developer has released many game patches to handle these annoying issues, many Windows players are still reporting the crashing issue. Since its release, several problems with the game have been reported, and Garry’s Mod crashing is one of them. Developed by Facepunch Studios and published by Valve, this game supports both single-player and multiplayer modes and is available on Microsoft Windows, Mac OS X, and Linux. Garry’s Mod, abbreviated as GMod, is a popular sandbox game first released in 2006.


It may be some addons or the map onto the server causing that as it happens on the same DarkRP server every time, but it's the server i'm mostly on these days since i'm working on it.And it happens after a really long while, several hours of gmod launched with several connect/disconnect to several servers. We both run the game windowed and have nVidia GPUs (GTX 670 for me, 650 for him if i remember well, with latest drivers -at least for me- and nothing exotic into gmod / nvidia settings). I personally disabled Aero but it happens to a friend with aero too. So i'm thinking about something happening with video rendering as it slows down the whole desktop display.

I forgot checking gpu usage when it happened last time (i was more upset because of what i just lost ingame) but CPU usage was far from being at maximum, that is for sure. During this time, it seems that my whole desktop is slow, as taskmanager (required to close the game) is slow to launch and its display is like "step by step" for 2 seconds (in any other case it displays instantly, i've got a quadcore and an SSD.). I'm still connected to the server, i can talk, move, but the picture i see is frozen. GMod's window freezes sometimes, after a few hours of game. Since a moment (can't remember when but a few months), i'm getting an issue that i guess only people running the game windowed get :
