WebEx and Microsoft Windows 7 don’t seem to get along 100% quite yet. If you are using WebEx on Windows 7 it’ll disable Aero during your session. However, if your session is over and you don’t get Aero back here’s how to fix it without rebooting:
1. Make sure you’ve closed/exited all WebEx components.
2. Right click on Windows Menu->All Programs -> Accessories -> Command Prompt and choose “Run as administrator.” You will need to accept a User Access Control warning about this.
3. Issue the commands:
net stop uxsms
net start uxsms
That should fix it.
Alternately (and potentially easier): you could restart the “Desktop Window Manager Session Manager” service via the Services administrative tool.
Three years later and Webex still has NOT fixed this