PC crashs after loading map~

So I just downloaded Gmod
The startup is normal , so is the menu
I minimized the settings cause my PC is quite weak
Then Start Game , I chose gm_construction
The game actually looks fine , runs smoothly , no lags

but like 5 seconds later it crashs my PC

thought it was something else beside Gmod so I tried again , and it crashed again

I don’t know what’s wrong and I hope I could find help here , cause I really like Gmod since it’s a game that cracks me up on gloomy days even though I just watched it on YouTube XD
The point I really really wanna play aand I hope that this danm PC isn’t the problem

Here is my specs :

Processor : Intel ( R ) Pentium ( R ) 4 CPU 2.40GHz
RAM : 750MB
DirectX 9.0c

750MB ram is not enough to play Garry’s Mod. 96MB VRAM is very VERY low too.

I thought the minimum requirements were

1.7 GHz Processor

From Steam Store page.