Unable to load "filesystem_steam.dll", plz help!

[Sub-Zero-6]

Hi every one..
i have a problem running half life 2, it gives me a message while opening it saying (Unable to open 'gamepath'\bin\filesystem_steam.dll) and it exits after i press ok..

anyhelp pleaaase...

thanks..

[Beerdude26]

Reinstall Steam, download it again from www.steampowered.com.