Cannot get on Bootup the Logon Window

You have a network installed, but on booting the system, you do NOT get a Logon Window ( First make sure, that this was not setup on purpose to avoid the Logon Window):
Check in the Control-Panel your network setup:

- you need a Network client (for Microsoft or Netware networks)
- the Network client MUST be your Primary Network Logon

You still do NOT get on Bootup the Network Logon Window ?
When you select in the Shutdown window:

to "log on as a different user", do you then get the Logon Window ?

This is a weird problem, which is caused by the installation of certain models of network boards (bug ?).
Solution ( as published in the Microsoft Knowledge base article Q141858 ):

Use "Regedit" to view your Registry and verify under the key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion
the Network\RealModeNet section:
do you have a key "AutoLogon" (value does NOT matter) ?
If yes, DELETE THIS KEY "AutoLogon" !

Then reboot your system, you should then get your Network Logon Window: