Dota 2 wont open

[Cpt. Creepjacker t(-_-t)]

Dota 2 will not open for me. I get to the "Preparing to launch" box, then after that goes away, it just stops working after a few seconds. I cant even get it to start up, it only goes to the preparing to launch. I downloaded Avira antivirus a day before, not sure if that had anything to do with it. But ive uninstalled it, reinstalled dota 2 TWICE, verified game cache, restarted my computer, and I have tried multiple launch options, including the two listed in the valve help page about dota 2 not opening. Nothing worked. Please, can anyone help me? I really don't want to have to stop playing dota 2.... This problem started in March, no one responded to my previous post :/

[Crystal]

hey, sorry to hear you are having a hard time after having tried all those steps
try a copy pasta job of this post in a thread here http://dev.dota2.com/forumdisplay.php?f=23