We can’t uninstall the Flash Player by simply clicking on the uninstall button. The standard uninstallation of the Adobe Flash Player is not successful, the reasons can be data corruption, hard drive errors or that somehow Flash files have been deleted manually that throw the uninstallation of course.
If there are 2 versions of the Flash player plugin in your OS(probably one for IE, the other for Firefox, Opera or Google Chrome etc), both need to be uninstalled before Flash has been removed from the system. Below is a tutorial about how to uninstall Flash Player completely, hope it will be helpful for you.
Here is the URL: