SpyMyPC is a powerful application that allows you to keep record of all the keystrokes occurred on your PC, so that you can monitor the activities of other people using it. The program can run in invisible mode - thus, nobody else but you will know that their activities are being recorded.
In addition, you can add a password to it, so that you are the only person capable of disabling it and of viewing the logged information.
Due to the program's nature, chances are that you will have to create an exception on your antivirus program to enable it and to be able to use it normally. Both when downloading the program's installer and when installing it, you will surely receive warning messages from your antivirus program. However, it does not seem to be harmful for you system in any way.
The program's configuration window is pretty small and simple. You can set the program to run automatically at Windows startup, turn it to invisible mode and define keyboard shortcuts to show the program and to view the logged information. Besides, you can optionally hide the program from any process viewing utility or from Windows task manager. Finally, you can manually start or stop the keystroke logging service at any moment - for which you will be asked to provide the selected password - and open the log viewer to see the recorded information.
In short, SpyMyPC is an advanced application through which you - and you only - will be able to know everything that has been typed on your PC's keyboard - both by yourself and others - without being discovered.