Control Panel item restrictions

I have a whopper of a problem.

I tried to get NERO to open and received a message to allow something in the
control panel, and I followed the directions, and did find the group settings
for read and write, and enabled something (cannot remember), but now nothing
will open without the following message, "This operation has been cancelled
due to restrictions in effect on this computer. Please contact your system
administrator."

I can open the Administrative Tools in the control panel, but once open none
of the programs inside can be opened, like computer management, event viewer,
memory diagnostics tool, etc., without getting this error message.

when I tried to open the Device Manager, I got the message, "This file does
not have a program with it for performing this action. Create an association
in the Set Associations control panel.

I have never been this lost before, and there are no bridges to jump off
here in Arizona high enough, so I do really need some help.

Thomboy