Garry's mod, Refusing to get passed the loading.

Above But.

The gmod beta boots up, gets to the loading screen then crashes.

I have verified and defraged both versions along with reinstalling them and wiping they’er folders clean, and have not found a single crash file do date.

Edit: Good god, I could use some help, I’m going bloody insane here!

System Info:

Operating System: Windows Vista™ Home Premium (6.0, Build 6002) Service Pack 2 (6002.vistasp2_gdr.120402-0336)
Language: English (Regional Setting: English)
System Manufacturer: Dell Inc.
System Model: Dell XPS420
BIOS: Phoenix ROM BIOS PLUS Version 1.10 A06
Processor: Intel® Core™2 Quad CPU Q6600 @ 2.40GHz (4 CPUs), ~2.4GHz
Memory: 4030MB RAM
Page File: 3606MB used, 4629MB available

Does the same issue occur for other source games?

Install/update DirectX.

I also am having this problem. I click on “Play” in steam, I get a Loading page that show a guy with a gun and some birds in a field with an hourglass cursor. I can wait for hours, never progresses. I have uninstalled/reinstalled all HL, CS:S, GM, and other valve software, ran the launch options like someone else suggested (-window -noborder -w 1920 -h 1080 -dxlevel90), also have made sure direct x was up to date. My video card driver version is 296.10 (Nvidia).

My specs are:
i7 920
eVGA GTX 460 SE Revision A1
eVGA X58 132-BL-E758 mobo
6gb (3x 2gb) DDR 3 OCZ Platinum PC3 12800 ram
Windows 7 64 bit SP1
1TB internal HD (OS drive)
620gb internal HD
2x 1tb external USB HD
1x 2tb external USB HD

debug.log is empty as well too.

I purchased this on Steam, and would love for it to work, I’ve done just about anything I can.

Fixed. I had to delete the Steam application, remove over 140gb of files (could probably have moved them if I cared about savegames) by removing …/Program Files (x86)/Steam folder, then downloading fresh from steampowered.com.
Then re-installed all steam apps (HL2, CS:S, Portals, TFs, etc.), then Gary’s Mod.