Do you have the correct username and password?
Yes:
Check the network control panel and TCP/IP settings are configured correctly.
No:
Correct it and try again.
Still not working.
Check the network control panel and TCP/IP settings are configured correctly.
For Both:
Still not working?
Re-install Dial up Networking.
Still not working?
Extract both Winsock's and rasapi32.dll.
Still not working?
Check for winsock2 on Win95, on Win98 remove winsock2 reg key and re-install DUN.
Still not working?
Remove any background applications and delete pwl files.
Still not working?
Modem problem.