By default, Windows Aero Glass transparency effect in Windows 7 is only able to give window frames and borders a frosted, blur effect which has nothing to do with the claimed transparency effect. Basically, with this effect users will be able to see through the window frame, but not completely. If you want to have a full transparent effect on your window borders in Windows 7, just apply this hack.

1. Click Start.
2. In the Search box, type regedit and press Enter.
3. Locate the following registry key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\DWM. If you can not find it, try this other key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\DWM.
4. In the right pane, right click – New – Create a new DWORD (32-bit) Value key and name it HideBlur.
5. Set the new key value to 1.
6. Restart the computer for the change to take effect.
7. As a side note, this hack seems to work only on the following Windows 7 build: 6956, 7048, 7106 and 7127.