counter-strike source - help

[OptimusPrime]

my brothers pc, wont run cs:s it worked some months ago... and now it just comes up with preparing to launch cs:s box, the box goes off and then nothing happens. :|

anyone with any simmilar problems?

[sL^lynx]

i had sim problem, fresh install worked for me mate!!!!

[Oddy]

delete clientregistery.blob might work