Gmod n00b, error installing with HL2!!!

So i downloaded LEGALLY, Half Life 2, then i went ballsdeep for GMod, i restarted, and opened Garry’s Mod, it shows start screen then, black… leading to desktop, and showing error prompt stating: HL2.exe has stopped working…

Could someone familiar with this error, please assist me on what procedures i follow to get my GMod properly installed so i can fuck shit up, sandbox style?

http://www.facepunch.com/showthread.php?t=980348

yes, thank you for such a post. ive read through that thread before. yet it seems to provide another problem, steam decides to tell me when i click on launch options, that “these options are for advanced users only” and gives me a bar to type things into, that i only find useful for explicitly expressing my frustrations.

well they are for advanced users, didn’t you read that thread, it tells you what to put in the bar. Also take a look at this page:
http://supportwiki.steampowered.com/wiki/Setting_Game_Launch_Options

Picture showing how to type in the box:

http://a.imageshack.us/img695/9639/alttab.jpg