My graphic card spposed to read 805MB but it only reads 64 of it , i changed my OS from 32 to x64 and still the same problem i have the lastest drivers too , my laptop is HP Pavilion g6-1300 Notebook PC series 1307se also here is a photo of the problem : http://i.imgur.com/Wnb72.png
In most cases, the computer manufacturer has already configured the system to use the maximum amount of graphics memory that is possible for your particular computer model. Sometimes you can change these values through BIOS level.
Check with your computer manufacturer if there are tips on increasing the amount of graphics memory for your computer model.
If you are interested in additional information see below: