If you only have one phone line at your location, or the same telephone line can be used to make voice calls as well as data calls, make sure that no one is using the phone line for voice communications at the same time you are trying to connect to the Internet.
Also, if you use the same telephone line for connecting to the Internet and sending/receiving faxes, make sure you are not sending or receiving a fax.
Make sure the phone cord is connected securely, and is not crimped or frayed in any way. If you are unsure, try a different telephone cord.
Most modems have two phone jacks on the back panel, one labeled line and a pass-through (for a phone or fax machine) labeled phone. The cord from the wall should be plugged into the line jack. You should try switching them to the opposite jack.
Make sure the wall jack is in good working order. If you have a modular telephone, disconnect the phone cord from the back of the modem and connect it to the phone. Can you hear a dial tone through the phone? If not, then their is a problem with the jack on the wall, or the line it self. If their is dial tone continue on here.
If you are in an office or other specialized environment and don't normally hear a tone when making voice calls, this will confuse the modem. You must configure the modem not to "wait for dial tone".
If you have voice mail service with your phone company and have messages waiting, there will be several skips before you hear a dial tone (Commonly called a stutter or shudder tone). The modem will not recognize this correctly. Check your messages before connecting to the Internet, or set the modem not to "wait for dial tone".
If you are using Windows 95 or Windows 98, in rare circumstances it may help to create a new Dial-Up Networking connection.
Recreating your Dial-Up Networking connection.
As a last resort, reinstall any modem files, drivers, extensions, libraries, etc. Consult your modem documentation or computer manufacturer for assistance.
If all this fails to pinpoint the problem, the modem may be damaged. Try a different modem or if your computer was built by a company such as Compaq, Dell, or Gateway call the computer manufacturer, and have it serviced by a qualified technician.
