Request Help: I lost privileges after changing Network ID to a Workgroup from a domain, even though

[Dan Gewirtz]

After changing the network ID from a domain to a workgroup, and rebooting
(and then for the first time logging in to a
login box without a domain-name selection list), I am no longer able to
control various basic settings: the task bar will not unlock;
I cannot change Advanced Settings in the Folder Options applet; other
Settings I successfully configure are not retained between logins;
I receive 'Access Denied' message when I try to open the Group Policy
applet.

(Background: I am no longer on a domain-based network-- the domain login
was a residue of a long-ago user-account setup,
but I had been logging into the defunct domain in the login screen until I
changed the Network ID from Domain 'Develop' to Workgroup 'Workgroup'.
My user is still in the Administrators local group and any new Admin users
I try to set up suffer the same behavior. The machine is a laptop
running XP Pro SP 1--originally a W2k installation that was upgraded without
incident.)

I suspect my problem is something basic related to Group Policy but I
obviously don't know anything about Group Policy.
Can anyone give me pointers on what the problem might be, or on which things
I should investigate?

Thank you in advance for any help.

Dan Gewirtz