My Windows 7 screen saver is set to come on after 10 minutes of inactivity. Also in my power options I have it set to blank the screen after 10 minutes. Neither of these ever come on, or else it may come on for a moment, then go back to displaying the logon screen.
I have a wireless mouse. I have read that this can often send signals and make the screen saver never come on.
It's hard to believe that anyone with a wireless mouse simply can't use a screen saver. What can I try? It's a MS Optical Wireless Mouse 2000.