After trying the above suggestions, if the stick still doesn’t work on your computer and it does others and if you installed windows yourself, make sure the drivers for the USB ports are installed. I don’t know about windows 8, but to check in windows 7, Start -> Control Panel -> System -> Device Manager -> there should be no exclamation marks or red ‘x’ on any drivers, or even question marks.
If there are, go to the website of the manufacturer of your PC with the model number (bottom of laptop or sometimes top), type it in and download USB drivers or whatever corresponds to USB, maybe like a south bridge driver, etc. for windows 8.1.