I'm try to uninstall my Yahoo mesengger but it appears the massage like this..
Yahoo messenger could not open INSTAL.LOG FILE

How can I uninstall it?

Try Revo Uninstaller: Revo Uninstaller Freeware - Uninstall Software, Remove Programs, Solve uninstall problems (http://www.revouninstaller.com/)

It's free for personal use. Use the "Manual" or "Advanced" setting.

Reboot your computer and try again after making sure that Yahoo Messenger is not loading with windows start up. See Preferences under Messenger menu and then General tab to stop that (first item). Programs will not uninstall if they are in use and components can at times still be in use even if you think you closed it out.