Windows 8 Registry values revert back hardware acceleration

[Hardy911]

I'm trying to turn on hardware acceleration for autocad. I changed registry values from 0 to 1 for hardware enabled and hardware available. After opening autocad hw/ac option seems turning on. But after some time it turns off automatically. I opened regedit once again and see that hardware enabled and hardware available values are reverted to 0. Is there any way to keep it 1 always??