Windows says that it can't negotiate a compatible set of protocols. What is wrong?

This error message can be caused by any of the following situations:
The network protocols used by the server do not match the protocols used by the Dial-Up Networking client.

The protocol used by the Dial-Up Networking client is not available.

The line protocols may not match.

WINS Resolution is enabled in Windows 95 Networking.

Solution #1
Make sure you have the correct server type selected in the connection's properties (PPP) by checking the following:
Double-click My Computer
Double-click Dial-Up Networking Folder.
Right-click on Internet Solutions icon. Select Properties ...
Go to server properties. If using an older version of Windows 95, you will see a 'Server Type' button. If using the newer Service Release 2 of Windows 95,98 or ME, you will choose a Server Type 'Tab' at the top of the window.

Confirm the following settings:
Type of Dial-Up server should be set to PPP
Under Advanced Options, only Enable software compression should be checked
Under Allowed Network Protocols, only TCP/IP should be checked

Solution #2
Verify that WINS Resolution is disabled in Windows Networking by checking the following settings:
Double-click My Computer
Double-click Control Panel
Double-click Network
Click once on TCP/IP, then click on Properties
Click the WINS Configuration Tab, and verify that Disable WINS Resolution is checked.