applications using Desktop Window Manager, a compositing window manager running on top of Direct3D 9.0Ex, and provides device driver interfaces required by Direct3D 10 runtime used in Windows 7.
Open Registry Editor (RegEdit).
Navigate to the following registry key:
HKEY_CURRENT_USER\Software\Microsoft\Windows\DWM
If the DWM registry key is not found, right click on Windows and then select New -> Key to create new branch and name it as DWM.
In the right details pane, create a new DWORD (32-bit value) named UseMachineCheck, and set its value to 0.
In the right details pane, create a new DWORD (32-bit) Value named Blur, and set its value to 0.
In the right details pane, create a new DWORD (32-bit) Value named Animations, and set its value to 0.
Restart the Desktop Window Manager Session Manager in Services in Control Panel (type Services.msc in Start Search), or run the following commands in a command prompt with administrator privileges:
net stop uxsms
net start uxsms
Attempt to enable and apply Windows Aero in Windows 7. Restart the computer if required.
The trick above also may work to enable Aero on Windows 7 and Windows Vista installed on virtual machine (VM), especially in Virtual PC 2007. VPC 2007 uses S3 as virtual display adapter, which is capable of running Windows Aero. When the guest Windows 7 or Vista OS uses software-based hardware check after hack above, it will find only S3, couple with actual Aero-capable video card, may allow Aero to run in VMs as in real physical machine.
