In computing uninstall means to remove an application from a computer. Uninstalling removes all files that were added to the computer when the application was initially installed. In addition, it might also remove files that were subsequently generated by the application. Frequently, however, uninstalling is not 100% effective, and a few orphan files remain.
In Windows, you can uninstall an application by selecting Add/Remove Programs from the Control Panel and then selecting the application you want to remove.