Error 731-Protocol Not Configured

Do this check list first.

Server Type, Advanced Options. Log on to Network is off.

Server Type, Allowed Network Protocols. Only TCP/IP is checked.

Server assigned name server addresses is on.

Server assigned IP address is on.

Use IP header compression is checked.

Use default gateway is checked.

TCP/IP Properties:

Obtain IP automatically, checked

Disable WINS resolution, checked.

It doesn't make a difference if I enter a Gateway address or not,

It doesn't make a difference if DNS is enabled or disabled,

No bindings are checked.

Modem Configure, Connection, Advanced. Hardware Flow Control is on.

I tried different modem speeds, which didn't make any difference.

Make sure you have Dial Up Adapter installed in Network.
Check: My Computer, Dial-up Networking, right-click on the connectoid, Properties, Modem Configure, Connection, Port Settings.

If you have selected FIFO, but don't really have a 16550 UART in the COM port that the External modem connects to, then disable this. This problem would only apply to an External modem, since any Internal modem would have the 16550 built-in. Also, if you do have a 16550 UART, adjusting the buffer sizes may help. The largest value is not necessarily the best.

If you sometimes connect but sometimes fail, the variety of error messages generally mean just one thing: the logon failed. The exact error message is usually meaningless. Other causes include noise on the phone line and a variety of problems at the ISP end.

Rebooting your PC or making meaningless TCP/IP changes usually just buys time. Each time you dial you could get a different routing to the ISP. And if the problem is a flaky modem or port on the ISP, some other poor sap may have it tied up next time you dial and you get bounced to a working one.

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