I'm running Home Premium 64 on a desktop and laptop, within a workgroup (not homegroup). When I try to lower my standard user account's UAC settings, it prompts for an administrative account and password, which I provide. After lowering, but not turning off, the UAC level, I get the error message "You must be logged on to this computer as an administrator to select this setting" (see figure). When I logoff standard and logon as an administrator (with either my own or the System account) I cannot go to Control Panel|Users|Manage other Accounts|standard user account and find any option to change its UAC settings. Any changes I make within either admin account apply only to admin accounts, not standard accounts.
Why does Win 7 prompt me for admin elevation and then tell me I have to be logged on as an admin, and then when I do so, provide no way of changing my standard user account?