how do I configure my video card?I put everything off and the image settings quality or what?

in LAN PC my cs is very bad, i play really bad and in home i play so good...in my home is ATI video card in LAN is Nvidia..

thx for all...

v sync off

vsync off

freq 75

at LAN champs i got only mouse problems... i dont know how to fix it :D and many mates at LAN dont know too so i play quite bad too :D

vsync off / freq 75 / hf