Hi Yavuz,
It depends what you mean by "set Screensaver". If you want to set it
running, I believe a P/Invoke call to SystemParametersInfo with a param of
SPI_SETSCREENSAVEACTIVE trick.
If you want to actually tell Windows what the current screensaver is (so
that when the user checks out display properties it's selected as their SS
of choice) I'm not sure that there's an API call that will help you, however
you could just programmatically alter the appropriate registry key.
Regards,
Alex Clark