Windows XP Login Notes
Windows XP handles blank passwords differently than other Windows operating systems. For this reason, it is recommended that you include passwords with all user accounts when you create them in Windows XP, whether or not you use Historian security. This is particularly important if you are running Historian in a 21 CFR Part 11-compliant environment.
In Windows XP, you can change the local policy to allow logins with blank passwords. However, domain policies can override local polices. Refer to your Windows XP Help for more information on changing security policies and the use of blank passwords.