My Windows 7 PC is asked for a Network Password (Windows Security Dialogue Box) on a home network when trying to access files on my XP machine on a two-PC home network. This was never been asked before. Windows 7 did a Windows Update last night and rebooted my computer. UserNames and passwords did not work. I did disable this feature from other recommendations... Local Policies > Security Options > Accounts: Limit local account use of blank passwords to console logon only. My XP machine can access files on my Windows 7 machine and does not ask for a password.