Hide Hard Drives Partitions(C:,D:,E: etc.)

This is a great trick you can play on your friends. To disable the display
of local or networked drives when you click My Computer.

1.Go to start->run.Type
regedit. Now go to:
HKEY_CURRENT_USER\Software\Microsoft\Windows\Curre ntVersion\Policies\Explorer

Now in the right pane create a new DWORD item and name it NoDrives(it is case sensitive). 

Now modify it’s value and set it to 3FFFFFF(Hexadecimal) .

Now restart your computer. So, now  when you click on
My Computer, no drives will be shown(all gone…). 

To enable display of drives in My Computer, simply
delete this DWORD item that you created.Again restart your computer.You can now see all the drives again.Magic.