Graphics problem?

I just bought gmod and cs:source and for some reason everything looks fine but my gun (any gun)
It looks all pixel-ish and has a bunch of different colors,what should I do?
And the only specs I know of my computer is it has 3 gigs of ram and is vista premium
If i move around the pixels change formation and can get bigger or smaller

Use speccy.

[editline]9th February 2011[/editline]

Oh, and try to go to Q -> (In the right upper corner you have tools, Utilities) Post Processing -> Make sure everything is checked off.

Operating System
MS Windows Vista Home Premium 32-bit SP2
Intel Pentium E2200 @ 2.20GHz 39 °C
Conroe 65nm Technology
3.0GB Dual-Channel DDR2 @ 400MHz (6-6-6-18)
ASUSTeK Computer INC. Benicia (CPU 1)
X193W (1280x1024@60Hz)
Intel® G33/G31 Express Chipset Family
Hard Drives
488GB Western Digital WDC WD5000AAKS-65YGA0 (RAID) 31 °C

IT’s the Intel thingy.
Intel + GMod = not a good combination.

err all my computer are intel,maybe I’ll have luck with my laptop

I’m talking about the Intel Graphics Chipset, not about the CPU.

oh lol
thanks datmeg you solved my problem

Sometimes you can fix this by adding

-dxlevel 81

to the Garry’s Mod Start Up Options
(which can be found by right clicking Garry’s Mod in the Steam Library and going to Properties)