I have run into things where it seemed that Administrator wasn't good enough. I'd like to know how to do that. If you can find "CREATOR OF ALL UNIVERSES" login mode, that would be even better.
For virus scans I need to be able to read and write any files regardless of permissions. Can SYSTEM do that? Can anything do that?
I don't know that much about the power of the SYSTEM account, other than the fact that it's more powerful than Admin.
Here's how to get a 'root shell' :
Open a command prompt. Invoke the 'time' command to see the current time (just press Enter again to not enter a new time). Now invoke
at xx:xx /i 'cmd.exe'
Where xx:xx is some time in the near future (one or two minutes ahead).
Wait a few minutes and the new command prompt should appear, this one is running under SYSTEM. You can start the task manager (taskmgr) from there, close Explorer.exe and run it from this new task manager (which is also running under SYSTEM) to get full use of the SYSTEM account.
As for logging in by default as SYSTEM, that requires some very complicated registry editing that I won't go into detail here (nor do I remember everything about it!)