You could use Microsoft's TweakUI to remove a username from the welcome screen and also have it set to be automatically logged into when you boot the computer. However, the user would then have to switch users to log into their own account. Thus, it would satisfy your first description of your goal but not the second.
Perhaps if you explained the reason behind this we could provide a more adequate solution?
John
I am looking for a way to do the following:
I would like, if it's possible, to create a hidden account on XP home. But when i turn on the computer, I want it to log on to that hidden account automatically, without showing that it did.
I want to turn on the computer...login to my account but have that hidden account logged into without me knowing it...any ideas?

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