XP file sharing; security policy

I'm try to access shared files on an XP machine and the XP machine asks that I log on, but doesn't recognize any logons. I'm able to access other XP computers on my network through their guest accounts (no logon required).

The only difference I can find between the machines I can access and the problem computer is the problem had no entries under "the computer is part of the following security groups" when I run gpresult. The other machines all have the same set of security groups.

net view lists the problem machine. I can also ping it.

I'm hoping that setting up standard security groups on my problem computer will let me access shared files. How do I set this up?

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Answering my own question:

This solved the logon problem (case sensitive):

net user guest /active:yes
ntrights +r SeNetworkLogonRight -u Guest
ntrights -r SeDenyNetworkLogonRight -u Guest