1) No context menu

What will you see when you right click on the
desktop? You will see a context menu which says arrange icons,
refresh,..and so on. Are you angry at your friend for not wishing you
for you B'day? Do you wanna play a trick on a newbie in your family who
is new to computers? This is a cool trick to play. By this tweak, you
will be able to disable the right click on the desktop or any
icons/files/folders/applications... But right click will work on
taskbar of the start button and registry. So, dont worry!!!
Open
your registry and you will see all unknown files like
HKEY_CLASSES_ROOT....... and so on. Don't panic. Follow this path.
HKEY_CURRENT_USER>SOFTWARE>MICROSOFT>WINDOWS>CURRENT
VERSION>POLICIES>EXPLORER. On the right side of the registry, you
will see two files(in general) named 'default' and
'NoDriveTypeAutoRun'. Right click on the empty space in the registry
and goto New>DWORD VALUE and name it as "NoViewContextMenu".
Remember, no spaces and N,V,C,M should be capitals. Right click on this
and click modify. The default value will be 0. Change it to 1. Note:
DONOT CHANGE THE HEXADECIMAL TO DECIMAL. Click OK. Close your registry
and logout. Bingo!!! Once you login again, right click wont work. Your
friend will be perplexed and the next thing he/she does is call the
system administrator not knowing that not all system administrators
will be knowing about registry. Now, to enable it again. follow the
same path and set the value to 0. Logout and then login to see the
effect.

2) Reverse the mouse buttons
This is a cool trick to
play on newbies. Actually, there are two ways to do this. One is
changing the settings in the Control panel and the other is through
editing registry. You can do it either way. But I prefer the second
way, which is challenging.
(i) Through Control Panel - goto
Start> Control Panel> Printers and other hardware> Mouse. In
Button configuration, enable the switch primary and secondary buttons
option and click OK. But remember, you have just swapped the mouse
buttons. So, for OK, you have to click the right mouse button. The
newbie will be perplexed. Well, this trick is good for left handers.
(ii)
Editing the registry - By default the left mouse button is the primary
and the right is secondary. Open your registry and follow this path:
HLEY_CURRENT_USER>Control
Panel>Mouse and on the right side of the registry, create this
String value(REG_SZ): 'SwapMouseButtons' and set its value to 1.
Bingo!!! You are done. Log out/Restart the computer.

You can
try this: Combine tricks 1 and 2. That means, this will result in
swapping of the mouse buttons and disabling the left click(once the
buttons are swapped). User is ready to call system administrator cuz he
feels that the system is behaving wildly.