is Resolution maximum 1280 x 1024 ?
 

initially the desktop screen display resolution was 1024 x 768
after changed it to 1680 x 1050 or a higher value ; it only displays 1280 1024 maximum resolution.

so what should be the problem ?

(installed in virtualbox P5Q Asus mainboard-QuadCore,Win7Ultimatex64).

please give me opinion.
I wantto use it fullscreen with full resolution support.
possible ?

thanks much.

You need to be little more specific on what graphic card you use.
Also it sound like it has to do with QE/CI, which means your hackintosh does not have proper setting for Graphic Card.

thank you for the comment,

external Nvidia GT6800 (1 gb)
mainboard asus P5Q-deluxe (mainboard does not include any integrated Graphic Card)

OS:Win7_x64
and installed in virtualbox latest version.

Chipsets Supprted by NVDANV40Hak.kext
0040 NV40 [GeForce 6800 Ultra]
0041 NV40 [GeForce 6800]
0042 NV40.2 [GeForce 6800 LE]
0043 NV40.3 [GeForce 6800 XE]
0044 NV40 [GeForce 6800 XT]
0045 NV40 [GeForce 6800 GT]
0046 NV45 [GeForce 6800 GT]
0047 NV40 [GeForce 6800 GS]
0048 NV40 [GeForce 6800 XT]
0049 NV40GL
004d NV40GL [Quadro FX 4000]
004e NV40GL [Quadro FX 4000]

I suggest you search for NVDANV40Hal.kext

well...m.
NVDANV40HAL.kext didnt worked me to increase resolution.

maybe because I installed iatkos under virtualbox.
I believe virtualbox does not allow or support for higher resolutions
or iatkos lion 10.7.3 does not know what is virtualbox

anyway
thank you so much.

reporting :
I found an information virtualbox only supports 5 resolution modes.
some of,....and 1280 x 1024 and 1400 x 880
so this is a virtualbox limitation and no solution for this problem.

VirtualBox emulates a graphics card. It does not have the guest additions for OS X so you are out of luck.