Hi,
Open system.ini
Delete all lines under
[Password Lists]
Go to Start/Find/Files or Folders, and type
*.pwl in the 'named' field.
Delete the files with the *.pwl extension that come up.
Now reboot
You should now get the login box. Type your name and password or leave the password field blank for no password
Not Yet?
Go to Start/run, and type Regedit.
Drill down to HKEY_LOCAL_MACHINE\software\microsoft\windows\current version\network\real mode net
Right-click on the Real Mode Net key, choose new>Binary value, name it AutoLogon, and give it a value of 01 00 00 00.
And here's a MS article:
Save Password Check Box Is Unavailable
Good luck,