I have Lenovo ideapad 330s and I tried to defrag my HDD as I never did since I got my machine two years ago. Windows couldn't see my HDD and appered like it is SSD. I looked everywhere and contacted Microsoft and talked with five different agents and no one was able to figure out the fix. I couldn't find anything on the internet as well so I though I need to share that with all of you guys and hope I was able to help. Peace