MSCONFIG error - access denied

"An Access Denied error was returned while attempting to change a service. You need to log on using an Administrator account to make the specified changes."

Why?

I am the only user.

 

First you should check and make sure that you are indeed logged on as the administrator.
start>control panel>user accounts

What service are you trying to change?

 

Yeah, I am the only user and it does indicate I am on as the Admin. The Guest option is even off.

I was changing some start-up services, disabling some that I could not do in Services (they are not there).

 

Try adding a new administrative user account and log into it.
See if this allows you to make your changes

 

You will get that message if you attempt to change a service from certain locations.
I believe if you go in through Control panel/ Administrative Tools then Services, you will be able to make the changes.