SolvedNeed Help PLZ

Everytime i try to open Crossfire it says ''File is changed W[2000] L[2] rez/rf012.rez'' and I downloaded rf012.rez and put it in rez File and it started to say ''File is changed W[2000] L[0] rez/rf012.rez'' Please i need help asap I need to play CF

You should do a clean install and turn off your a/v software.

How to do clean install ?