To deactivate your account, you should remove all personal details and make yourself unsearchable. This way no one can search for you using personal information:
For XP: Under the Start menu, go to the Control Panel, and select Add or Remove Programs. Scroll down and select ooVoo, then click Remove.
For Vista : Under the Start menu, go to the Control Panel, and select Programs and Features. Select ooVoo and click Uninstall.