The problem is almost always caused by 3rd party programs running at startup. In my experience with it it's really hit and miss. I've had antivirus programs cause the problem. I've seen Dell software cause it. I've even had WLAN management software, touchpad applications, eco management tools, etc cause it. It's almost always on systems that were upgraded from 7 to 10, but I've seen it on 8 ups too. it's most likely caused by unsupported or outdated software that is running on the machine. Windows 10 seems to be incredibly sensitive in this aspect.
I would suggest managing your startup programs and services with msconfig. Only run what is necessary for Windows to operate. If you leave any other 3rd party stuff make sure you uninstall them and then reinstall with the latest up to date version. Also be sure to check scheduled tasks and see what is running on schedules with taskschd.msc.
I would also suggest uninstalling your antivirus software and getting the latest version via their website. Don't just update the exisisting version.
If you haven't yet you should also try running sfc /scannow
Edited by ChiefTech, 10 April 2016 - 06:36 PM.