Sys_Keylog Advanced is a simple utility that lets you secretly save all the activity that takes place on your computer. Doing this lets you keep a record of every key press that has occured, web pages that have been viewed and even the programs that have been opened. All this info is organised in a log file that can be programmed to automatically arrive in your email at a particular time.

The program installs in the background meaning that the user under observation won't notice any change to their system. What's more, it's also password protected.