I want to do simple thing - change refresh rate.
I wrote simple code:

LPDEVMODE newres;
newres->dmSize=sizeof(newres);
EnumDisplaySettings(NULL,ENUM_CURRENT_SETTINGS,newres);
newres->dmDisplayFrequency=70;
ChangeDisplaySettings(newres,CDS_UPDATEREGISTRY);



BUT it does'nt work.
I know exactly, that this frequency is supported at this resolution, 'case I can setup it manually in properties dialog. But this code does't work. Why?