That's a new one for me. I can help you see if the program file went missing. Another option is downloading a different, free slideshow screensaver.
A screensaver program need only be present in the Windows System folder for Windows to show it in the list. No special installation or registration is required beyond that. The My Pictures Slideshow program file is called "ssmypics.scr."
Let's see if we can locate your screensaver:
- Open the Start menu and select "Run"
- Type cmd in the text box
- A window called "Command Prompt" will appear. Type the following:dir %windir%\ssmypics.scr /s
You should see the file in two places: a folder called "system32" and a folder called "dllcache." If you don't find it at all, you will need to reinstall Windows to get it back.
If you find it in dllcache but not system32, Windows File Protection (WFP) must be disabled. I would be very suspicious at this point. You may have a virus or spyware. Or you may have security software that disabled WFP. Either way, get your system checked out. The Knowzy Software Library has free Anti-Virus and Anti-Spyware tools you can download.
If you find ssmypics.scr in both places, I suggest that you reboot your computer and look again. The exact title you should see in the screensavers list is "My Pictures Slideshow."
If all of this is too daunting, you may just want to give up on My Pictures and install a new slideshow screensaver. An excellent alternative is picsaver. I'm also a big fan of Google Photos Screensaver, though it has limited configuration possibilities.
Good luck and let me know how it works out.