Aero effect on win7 x64 with dual view

Aero has been disabled for win7 x64 since it was installed on my pc. The graphic card is Nvidia Geforce 7300. I updated the driver to the latest one, but still no lucky.
There is only one error in windows event log:

The Desktop Window Manager has encountered a fatal error (0x8007000e)

The error indicates ‘out of memory’. This make sense. I connected two monitors to the graphic card and enabled dual view by setting Multiple displays to ‘Extend these displays’ in display settings. And the ‘dual view’ consumes more video memory. (

After disabled the second monitor, Aero effect is back.

After install a new graphic card, GT240, Aero effect can be enabled under ‘dual view’ mode now.