So I live with a couple of jerks, who like to leave their computers on 24/7/365. To conserve power when these guys are away for hours on end, I shut off their idling computers. They don't really do anything important on them other than look at porn. I, on the other hand, nearly always shut off my computer, leaving it on when I'm not around only for legitimate reasons. I thought I could keep it Locked (Windows Key+L) and leave no way to have it shut down (including pressing the power button to initiate shutdown). That isn't the case, as there is a Fast User Switching option below the password box that, once clicked, shows a shut down options box on the next screen. Bah. So let's disable that box. Too bad, I don't know how. Instead, you can disable the Switch Accounts button in about five seconds of work. Here's how:

• Hit Start and type regedit.exe and hit enter. Now we're in the Registry editor where we'll put in some text. Lets find the place to put it.
  
• Using the menu tree on the left navigate to Computer > HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > Windows > CurrentVersion > Policies > System
  
• On my screen I was looking at about 17 listed items. We're going to make a new one. Right click the body where the keys are listed. Select New then Select DWORD (32-bit) Value. It will come with with a New Item, change the name to HideFastUserSwitching (Make sure you don't put any spaces before or after the name, as it won't work.)
  
• Now right click the item and select Modify. Change value data to 1 and click OK. The setting should already be Hexadecimal.
  
• You should now have an item that says HideFastUserSwitching REG_DWORD 0x00000001 (1)
  
• Close the Registry Editor and lock your computer with Windows+L. "Switch User" should no longer be present and therefore not allowing anyone to access the Shut Down menu on that screen.
  

Now the only problem you would have to worry about after a Lock is someone holding down the power button to have your computer to cut its own power, or having someone physically cut power to the system. If you find a solution to that, let me know. Guard dogs maybe?