As with anything, a few people are having trouble with Win10. A major update is expected soon.
"Microsoft's original plan, we've heard from various sources, was to roll out Windows 10 in October 2015. Instead, due to OEM pressure, Microsoft began rolling out Windows 10 in late July. An update with a bunch of missing features, known as Threshold 2, is coming later this Fall."
Next year Spring & Fall, a pair of "Redstone" updates will continue improving the stability.