If you can use something, it's useful. Useful things are handy for whatever you're doing. If something is just what you need or you just find it helpful, then it's useful. A hammer is useful in building many things. Coasters are useful if you don't want a coffee table to get stains. College degrees are useful â or necessary â for many careers.
Where is the security key on a comcast modem located? The security key on a Comcast Modem is located next to the serial  number of the unit. Sometimes the serial number is the number used  as a security code if it is not printeâ¦d on the device. (MORE) 1 person found this useful.
Find your password on your hardware. Note. If you need the default security key or password for your wireless router, contact your Internet service provider or router manufacturer. However, you may be able to find the security key or password on the bottom of your router or in the routerâs documentation. Look for the following terms: â¢ Security Key.