You might want to try this, as long as you have at least one User account that still is a Admin-equivalent...
1. Select an existing User, or create a new User.
2. Give this User full rights to the Root of each Volume Object.
3. In NWADMIN32, right-click on the ROOT Object and select TRUSTEES OF THIS OBJECT.
4. Select ADD and add the selected Username to the list.
5. Make sure that you select EVERY check box under OBJECT RIGHTS and under ALL PROPERTY rights.
Hope this helps.
Good Luck!