There is an uninstaller listed in the start menu but when I click on it, its not there and Windows tries to search for it. How come?
You uninstalled OE-QuoteFix and then reinstalled it to the same directory without rebooting in between (although the uninstaller told you not to do so). The next reboot killed the uninstaller. If you intend to install to the same directory anyway, do not uninstall, simply install over the previous version. Don’t worry, it doesn’t result in a mess, the installer will clean up everything beforehand.