Error 691: The computer you are dialing into cannot establish a Dial-up Networking connection
Error 635: There was an unknown error
Error 718: Timed out while waiting for a valid response from the remote PPP peer

These errors can be a pain, as there are many causes for them.

Reboot the computer. If you're lucky this is all you'll need to do. This resolves the issue most of the time. However if the issue keeps recurring, there is likely a problem with Windows or your modem, so you may need to have it serviced to resolve the issue entirely.

Windows 95/98? Check your username/password. Especially in Windows 95/98, you may get this error after being prompted to enter your password again a few times. Delete everything out of both the username and password fields and enter them again. If it still doesn't work (and you're still be prompted to re-enter the password) contact our support department to ensure your account is active and in good standing.

Update your modem drivers. This error can be caused by problems with the modem drivers, which are used by Windows to communicate with your modem. Contact your hardware vendor to obtain the most recent drivers for your modem.

Try to eliminate noise/interference. The problem could be caused by interference or noise on the line corrupting the username/password between your computer and our authentication server. Many times line noise is caused by something on the line external to the home, but due to the nature of telephone wiring and its susceptibility to interference there are several things you can do to ensure you are not contributing to line noise inside the home, such as:

• Surge protectors/line splitters/line filters -- These devices can cause interference on your phone line, and can also weaken the signal. Line splitters and filters are designed to be used on voice lines, which need very little signal strength in order to operate. Your modem however uses all the available bandwidth on the line, and it will notice problems before you will experience them on a voice line. Try plugging the phone cable directly into the wall jack. You want to have the phone line go directly from the modem jack in the computer to the jack in the wall.
• Use a shorter phone cable. Long phone cables--particularly cables that are joined together with cable joiners--can cause problems because the longer the signal has to travel the weaker it can get and the more susceptible to interference. This is primarily due to how the wires in a standard phone cable run straight down the cable, not twisted together like network cables (which do so to help funnel the signal down the wire further and help shield from interference). If you are using a long cable, try using a shorter cable to test (you may need to move your computer to do this).
• Unplug other devices from the line. If you only have one phone line--or if you have a second phone line for the computer that also has other devices connected to it (such as a phone or a fax machine), try disconnecting all the other devices on the line. Sometimes phone devices feed back noise onto the line, particularly portable phones and answering machines. If this resolves your problem you may want to disconnect these devices when you're connecting, or look into getting a dedicated line just for the computer.
• Move the phone cable at least 2 feet away from devices that generate interference. Power cables (especially the big black AC power blocks many electronic devices use), speaker wires, air conditioners, and other devices can generate electrical fields, which phone cables are very susceptible to.
• Contact your phone company if you know there are problems with your line. If there is an obvious problem with your line (you hear other conversations on your line, there is audible static or noise of some sort on the line) you will need to contact your local phone provider to resolve the issue. With issues like this, you will NOT be able to establish and maintain reliable internet connectivity until they are resolved. It is important to approach the phone company from the standpoint of voice problems, as phone companies are not obligated to provide reliable data communications over voice lines (besides fax, which only needs up to 9600kbps to function).