When you start your computer try and access the BIOS. See if your keyboard shows up in the menu. If your keyboard is unresponsive even at start up, I believe that it might need to be replaced. Of course you can also try to tap F11 as soon as you press the power button to see if this will launch Recovery Manager. If it it does, you can use this to reinstall the OS and you know that your keyboard is working. Use these guides to work on your Compaq. Hope this helps, good luck.