Private Desktop 

Say you're at your computer doing something private and someone comes in... Private Desktop will allow you to escape to your "public" desktop with the push of a button. Private Desktop allows you to keep a second password protected scree.
password private privacy desktop lock hotkey windows

Computer Lock Up 

Computer Lock Up utility enables to lock computer access quickly as well as efficiently by means of password protection at the time the user is absent. The program maintains standard and transparent modes of computer locking.
computer lock up transparent screenlock lockup lock up security ctrl alt del access lock computer lock best lock security lock