Here is a simple way to add a domain user to the local administrators Group on a computer using the Remote Background feature in GFI RM
Select the Computer in the Portal
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Select the Computer in the Portal and then click the Remote Background Button.
Remote Background
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The first is to check if the user is a local administrator. Run the command
net localgroup administrators
This will return the Group Membership and you can look to see who is a member.
Add User to the Administrators Group
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You can then add a user to the Group with the command
net localgroup administrators domain\userr /add