Open the Start Menu, type View Installed Updates and press enter.
Search for Internet Explorer 9 on the list, please note that I could take a while for the entire list to load.
Once you found Internet Explorer 9, double-click it. You will then be prompted if you wish to uninstall it or not, click Yes. It should start uninstalling it then.
After completing the above steps, please click the 'Uninstall Program' link on the left side pane.
