Updated to Windows 10, lost a bunch of contacts.  I am using Windows Live Mail but I never sign in to my Windows account when I use this email application.  Did creating a sign in during the Windows 10 upgrade also sign me into Windows Live Mail (and also consequently lost a bunch of my contacts?)  How do I get them back?  Do the contacts reside also on my local drive that I can access to restore the missing contacts?

[Original title: missing contacts]