it's just plugged into the usb port on my pc, but the led is still showing that it's connected. I even tried to reinstall the driver and unzip the cgminer again, but it still keeps saying no usb devices found.
Your first concern should be that your hardware is working okay. Check if your USB port is working okay. Plug a USB mouse, flash drive, or something in the same USB port.
You can also see if your gekko is recognized on a different USB port plugged in directly into the computer without any cables, USB hubs etc in between.