Re Outlook. I keep my Outlook in "My Documents" in my data partition along with word, photos, nusic etc. I then use freefileshnch to make a daily back up. Never had to use the back up but this site seems interesting. I wonder if ther is a hidden back up somewhere? Could you try Recuva to find the lost contacts?
Windows 10 Home vs Windows 10 Pro comparison: Here are the extra features you get in the Pro version