Windows 7 does not enable Aero Glass effect on its own. Moreover, you need to verify whether your version of Windows 7 supports Aero feature or not. If you find that your Aero feature is not enabled or working in Windows 7, try these troubleshooting steps.
Aero not working in Windows
1] Ensure that your version of Windows 10/8/7 supports Aero. Aero is supported on Ultimate, Home Premium, Business editions.
2] Ensure that your Graphic card supports WDDM (Windows Display Driver Model)
3] Right-click on the desktop, select Personalize. Click on Themes and select the default Windows themes. Next, in Windows Color & Appearance, ensure that Enable Transparency is checked.
4] Open Run box, type Services.msc and hit Enter to open Services Manager. Ensure that ‘Desktop Windows Manager’ Service is set on Automatic.
5] In spite of doing all this, you still find that Aero does not work, or your Aero has stopped working, simply copy-paste the following command in CMD window, and hit Enter.
This will re-enable Aero by flushing it.
Even if you find that your Flid3D is not working or disabled, you may try these steps.