Garrys mod crashes upon startup.

Im having this problem with gmod where it just crashes on startup.
Things ive tried-
-reinstall the game
-reinstall steam
-set launch options(-dxlevels)
-go back on windows updates
Yet none of these are working.
does anyone know the problem?
Also verified and all that stuff.

[editline]9th August 2017[/editline]

Problem solved i should read the faqs better.
This solved it
hl2.exe appears for a few second and then disappears

Some AMD graphics card users reported that enabling following setting in the control panel solved the issue for them:

Radeon App > Display > Enable Scale with GPU