Cant Play Single Player!

When i try and play single player it gets to loading materials it stops loading and crashes (i cant tell intill i use task manager to see). I have a new computer.

Processer:I7 2.66 ghz
Gpu :Ati Radion 5770
Ram :3 gb
OS :32 bit Windows 7

I would like to fix this (without reinstalling gmod if posible).

Still Same Problem any ideas?

You’ll have to try reinstalling it, sorry.

Rename your garrysmod folder to garrysmod.old and launch it up again.