If you are using windows you need to go to the device manager tab and look for modems in the list if you see it and you see a question mark or some other mark to the right of it you should right click on it and choose properties, when you get to properties click on reinstall driver, this is where you will have to download the right driver if you do not have your drivers on hand which means you should download the right driver for you modem before you follow the steps outlined.