Boot problem - no logon mask

[Giobibo]

Since some weeks I have a strange problem under win2000 pro.

When I boot the system, all works fine, all driver are loaded (the HD
works anyway), but the logon mask (where you insert username and
password) does not appear.
But the system is correctly booted, because I can see this computer from
all other PC over the network: I can access to all shared folders, I can
read/write documents on those shared folder...
The only way to work is to make an hardware reset and reboot the system:
well sometimes after the first reboot I can see the logon mask, but some
times I need 2-3 reboots to get finally the logon mask.

It is odd that the problem is not always, I would says 30-40% of all
boots: anyway enough to find a solution!

Could anybody help me?
Thank you.

 

[Giobibo]

I forgot to add some infos:
- win2000 is updated with SP4, IE6SP1 and all recent MS patches (I hope,
the most important one)
- no virus has been found with un update scan (AVK)

 

[Read]

maybe you have it set to logon automatically
Control Panel > passwords

 

[Giobibo]

maybe you have it set to logon automatically
Control Panel > passwords

No, it isn't.

The problem is that when I get this strange behavior I cannot access to
the desktop, I have just the blue wallpaper of win2000, but no explorer.

Thank you anyway for your answer.