(Important)Plz Help Me!!!

Guys yesterday i was playing some css and after some time i stopped .After Some hours i opened again my pc and i join a dota game in battlenet.after 2 hours i tried to open css but nothing happened,i tried to open steam although the same thing happened....i have tried it a lot and nothing happened.i also restarted the pc a few times but again anything have happen.plz help me.. :'( :'( :'( :'( :'( :'( :'( :'(