Why can't Win95 negotiate a compatible set of network protocols"?

We have observed that a small number of Win95 users seem to have occasional problems connecting. The symptom is that Windows 95 will dial the number, successfully login and then immediately fail during the PPP negotiation phase with a message similar to: "Dial up networking could not negotiate a compatible set of network protocols you specified in the server type setting". Often rebooting the computer can clear the problem. Sometimes doing nothing but waiting a few minutes and then redialing will cause the problem to disappear. For some users, they must remove and then add back the "TCP/IP" networking protocol to clear the problem.

The primary cause for difficulty seems to be related to the NetBEUI, IPX/SPX, and TCP/IP protocols are used by default for a Dial-Up Networking "connected". (Hey, we don't name these things... "connected" is Microsoft's name for the Dialup Networking configuration that you created to connect).

However, for use with Internet Service Providers, nothing should be bound to the Dial-Up Networking Adapter but the standard Internet TCP/IP protocol. Something will occasionally cause Win95 to bind other protocols to the adapter as well. This is normally harmless and the only effect is to slow down the login process as Win95 has to timeout on the unsupported protocols. Apparently, occasionally this process fails and the error message "Dial up networking could not negotiate a compatible set of network protocols you specified in the server type setting" error appears.

We are not sure what causes the normal timeout process to fail. Our guess is that variable timing delays (called 'race' conditions) introduced by a particular computer configuration, modem type, connection data rate, telephone line quality and load on our communications servers can all play a part.

Since Internet Service Providers only support the TCP/IP protocol, we suggest removing the NetBEUI and IPX/SPX protocols so that Dial-Up Networking cannot un-intentionally bind to them.

To change your Win95 settings to be compatible with Internet Service providers, make certain the NetBEUI and IPX/SPX protocols from the Control Panel folder - Network section have been removed. We also suggest the additional step of removing the Microsoft TCP/IP protocol, even though it will be added again later.

Once the protocols have been removed, restart Win95 and follow our instructions for configuring Win95 to connect. When configuration is complete open the "Dial-Up Networking" window, right click on the connection icon then select "Properties". In the properties configuration window that appears click the "Server Type" button and make certain that the "Log on to network", "NetBEUI" and "IPX/SPX Compatible" boxes are NOT checked.

If the "Dial up networking could not negotiate a compatible set of network protocols you specified in the server type setting" error continues to appear, examine your modem type setting in the modems icon of the control panel. The error may occur if Windows 95 was unable to correctly identify your modem brand and model or it was otherwise set incorrectly.

We suggest contacting the manufacturer of the modem for advice on how best to configure Win95 and the modem to interoperate. If unable to contact the manufacturer or you don't know who the manufacturer of the modem is, we have had good luck with just setting the modem type to be one of the appropriate "(Standard Modem Types)" choices in the modems icon of the control panel.