SPI_SETSCREENSAVETIMEOUT not working on Windows 7 using Python and ctypes

I'm using ctypes to call the SystemParametersInfo() API function to set the screen saver t开发者_运维技巧imeout value. It works fine on Windows XP but not on Windows 7. The code I'm using is the following:

import ctypes

user32 = ctypes.windll.LoadLibrary("user32")
user32.SystemParametersInfoA(15, 5, 0, 3)

The code invokes the screen saver every 5 seconds. Strangely enough, I can see that the registry location containing the timeout setting has been updated, even though the screen saver itself does not appear.

Any ideas?

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That works absolutely fine for me. My guess is that you have no screensaver selected.

When I changed my settings and selected "(None)" as my screensaver then the call to SystemParametersInfo had no effect.