To force quit Device Detector, simply access the Task bar using CTRL + Shift + Escape then switch to the Processes tab. Locate the Device Detector in the process list and right click it. Select End Task and then proceed with the installation. Additionally, you might want to disable it to prevent future errors. Go to Start > Run > msconfig and select the Startup tab. Locate the Device Detector application in the list and untick it. Reboot the computer and you should be able to install it. You can choose one of the two ways.