I'm not sure if you can do this with the "admin" user but you can try to edit this user and then disable it instead of deleting it
I just double-checked and the "Enabled" and "Disabled" buttons are greyed out too.
You will not be able to delete the account you are signed in with. You would want to login to the secondary admin account that you have defined. Once in the dashboard return to the user management section and select the admin account. You should now have options to edit or deleted the account.
Thanks for your reply. I have already logged in with one of the other EPO admin accounts I created. But it still has all the options greyed out on the original administrator account when I try to edit the permissions.
You can't remove or disable the original admin account, I'm afraid, as it's essential to the running of ePO. A lot of the server tasks, queries and so on are "owned" by this user, so deleting (or severely restricting) it would break a lot of things.
If you try and delete it, you'll see a red "This user cannot be removed" message. However you can edit some of its properties, so if you're worried about unauthorised usage, I would recommend changing its name to something non-obvious and (obviously) giving it as strong a password as possible.
This did the trick. I renamed the administrator account and changed the password to be sure.
Thanks for your help with this.