Можно попробовать через HIVESYS.INF (здесь разрешение 800x600)
Код:
[AddReg]
HKLM,"SYSTEM\CurrentControlSet\Services\VgaSave\Device0","DefaultSettings.BitsPerPel",0x00010001,32
HKLM,"SYSTEM\CurrentControlSet\Services\VgaSave\Device0","DefaultSettings.XResolution",0x00010001,800
HKLM,"SYSTEM\CurrentControlSet\Services\VgaSave\Device0","DefaultSettings.YResolution",0x00010001,600
HKLM,"SYSTEM\CurrentControlSet\Control\Video\{23A77BF7-ED96-40EC-AF06-9B1F4867732A}\0000","DefaultSettings.BitsPerPel",0x00010001,32
HKLM,"SYSTEM\CurrentControlSet\Control\Video\{23A77BF7-ED96-40EC-AF06-9B1F4867732A}\0000","DefaultSettings.XResolution",0x00010001,800
HKLM,"SYSTEM\CurrentControlSet\Control\Video\{23A77BF7-ED96-40EC-AF06-9B1F4867732A}\0000","DefaultSettings.YResolution",0x00010001,600
