GMod not starting up

Hardware info:
-Processor: Intel Core Duo 2 up to T9300, 2,5 Ghz of speed and 800 Mhz of FSB, 6 MB of cache L2
-RAM: 4GB
-Graphic Card: NVIDIA GeForce 9500M GS with 512 MB of memory
-Operative System: Windows 7 Ultimate 64-bit

No Addons

Problem:
Whenever I try to start gmod it says “Prepearing to start up Garry’sMod …” and then it shows this:

Are you using legit steam?

[editline]07:48PM[/editline]

Also did you try to reinstall steam or gmod or maybe both?

Of course I’m using legal steam .-.
I’ll try reinstalling gmod

[editline]07:10PM[/editline]

nothing

Exit steam and delete clientregistry.blob from your steam folder. Then reopen steam.

Nevermind, I verified the files and it deleted the wrong one, it’s all ok now.