Hack Windows 7 to Force Enable Aero
1. Open Registry Editor (RegEdit).
2. 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.
3. In the right details pane, create a new DWORD (32-bit value) named UseMachineCheck, and set its value to 0.
4. In the right details pane, create a new DWORD (32-bit value) named Blur, and set its value to 0.
5. In the right details pane, create a new DWORD (32-bit value) named Animations, and set its value to 0.
6. 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
7. Attempt to enable and apply Windows Aero in Windows 7. Restart the computer if required.[Via Digital Life]

...