Windows 7 DWM / Aero problem

Try this first:
To enable Aero
Click on the Start Button and in the Search box type Aero. Now click on Find and Fix problems with transparency and other visual effects.. Immediately an Aero box will pop up. Click the Advanced link and place a check in the box to automatically fix errors.
No click the Next button and you'll get a progress bar detecting problems. If the results all are checked with none of them failed, then your computer can support Aero. The Aero feature will work immediately, so just choose Close the Troubleshooter.

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This works on the 32-bit version. make sure to create a Restore Point just in case.

Enable Aero in Windows 7 with Registry Hack

1. Click on Start and type...