I tried again with windows7 and Its not solved. There is already unchecked "Maximum Memory" option in msconfig, boot tab. i setup again windows 7 64bit and i got total video memory 708MB on dxdiag. 
:hel...
I tried again with windows7 and Its not solved. There is already unchecked "Maximum Memory" option in msconfig, boot tab. i setup again windows 7 64bit and i got total video memory 708MB on dxdiag. :hel...