So wanted to slowly add my wife as a user to use windows 10 ( try and get her off of outlook 6 in windows XP) ., so got her profile ( ran short cuts to her folders undr another drive to access her folders .., added .. but noticed everything I tried to add I need administrative approval.. so I made her administrator too..
so far so good..
the next day after I log into windows 10 from a PC reboot the PC scanned my C: drive (win10) and reported errors .. re-scanned thru.. rebooted same scenario scanned again again.. reboot attempt -no more windows 10 log in! it took me to the safe mode screen in which I had two / options) ..

1. reinstall save my folders and reinstall windows 10.. or 2. reinstall windows 10 all new . .
I picked option 1.
upon the restart I now had my wife's desktop with no installed aps' . ( I knew that ).. but all my log in (user) under my name totally gone ! .. The main account was 24 months old .. the new one 24 hours old ..

No second log in .. Just my wife.
So I have been over the past day reinstalling rebuilding and reloading al lthe aps and emails and browsers and programs etc etc etc .. question:

What the hell happened! what could I have done to prevent this? what could I have done to rescue myself? all my backups previous restore points etc don't appear anywhere .. I thought my login thru microsoft of my own Microsoft account (login screen) would reload everything . .Not ..

should I have used windows.old ? and if so how??

( I'm still not sold on win 10 over win xp but Microsoft has us over a barrel ...

thanks