If you use Remote Desktop a lot and you get a message about your password needing to change, you can't use:
Ctrl - Alt - Del
because that will change the password on your actual PC - not the box you are RDC'ing to.
All the documentation states:
Ctrl - Alt - End
but sometimes that simply doesn't work.
In such cases, in the RDC window, try Start - Run - OSK.
This pops up the On Screen Keyboard.
Than hold down Ctrl and Alt on your actual keyboard and then click Delete on the OSK.