A couple of things here. First, make sure your usb ports are working on your computer. Try plugging the unit into a different usb port. For example, if you usually plug it into the back, try plugging it into the front. If this doesn't work, get a "Powered" usb hub. Your usb ports work on 5volts. Even when they start to fail, they will recognize "non powered" devices like thumb drives or camera cards. Another issue is that the power supply may be failing. Make sure you're using the power supply that came with the drive. If you say it works on your laptop, I'm thinking that your pc's usb port might be failing. A powered hub should resolve this issue. Hope this helps.