Please fill in your specs by going here
. This will allow us to offer more accurate help.
What's the exact model of your video card ?
I'm assuming it's a model that can be unlocked. Most new PCI-Express based cards are almost impossible to unlock in contrast with older AGP versions that could easily be unlocked.
The only way to find out if you can unlock it is to use Rivatuner
and try it.
For more info on how to do it... check out this webpage
it's all explained there (with screenshots).