Sinon tu fais ca :
 
Go into Regedit, find key:-  
HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E96E-E325-11CE-BFC1-08002BE10318}  
Under there will be folders numbered 0000, 0001, etc. The highest one will be your current monitor setting. Open that folder and there's another one called MODES, and a further one that will be the max resolution of your monitor (e.g. 1600,1200)  
In there is a key Mode1 with a value such as  
27-96,55-160  
Change the highlighted value to your desired refresh rate  
Now repeat the process for all your folders CurrentControlSet, CurrentControlSet001,CurrentControlSet002
 
 
Ca marche pour tout les drivers et tous les types et marques de CG.