In order for the In-Game Overlay to work properly on Windows 7, Aero needs to be enabled. It is the functionality that allows Windows and Overlays to be transparent. If Windows Aero is disabled for Windows 7, you will not see the In-Game Overlay for any function. However, those functions like recording and bookmarks will still work.
Usually by default, Aero is enabled, but depending on your Windows theme it may be disabled. Follow these steps to ensure that you're using a theme where it is enabled:
- Right-click on your desktop and choose "Personalize"
- Then select one of the default "Aero" themes available
Some games will disable Aero when they are opened, even if you are using an Aero theme.