Vray Frame buffer save images

can anyone tell me how to unlock the vray env variable so that i can save and reload images in the vray frame buffer? seem to remember you had to edit a text doc and set some variable to 1?

I am assuming you are not using 2.0, which is now an enables feature.

Right click My Computer
>properties>Advanced>Environment Variables (user variables)>New
Name: VRAY_VFB_HISTORY
Variable value: 1

opp there it is. great