Garry's Mod refuses to start.

Right, I recently came back to Garry’s Mod, and last played it yesterday without any problems at all.

But now, when I try to start it, it simply won’t. I just get stuck at the loading screen with the man on Construct with the physgun over his right shoulder and the toolgun in his left hand.
It simply just freezes there. I left it for 30 minutes, to no avail.
I’ve reinstalled GMod, but that did nothing.

Specs:

OS: Windows 7 Ultimate x64

GPU: XFX ATi Radeon HD 5770 XT

CPU: Intel Core i5 750

RAM: 4gb DDr3 Crucial 1066 Mhz

Mobo: Gigabyte P55 UD3

HALP.

[editline]04:47PM[/editline]

Uh, seems like I “Solved” it.

I forgot that I re-installed Episode 2 last night without actually running it.
I ran it now, and GMod starts up and runs like it should.