I found this issue with my new HP Desktop after only using it for a couple weeks. I've tried everything! FINALLY FOUND THE ISSUE!!! My wireless HP printer worked but would not scan to the computer, would only scan from HP's web based controls. I completely uninstalled all of my printer files and did a generic printer install from control panel. Generic icon is all that shows now, but everything is working perfectly! Scan to computer works as does my screensaver and sleep mode.
Makes no sense, after all these years you would think Microsoft would finally have this all figured out, but I guess not................................After Win Vista, who would think this would all still be an issue.