I recently purchased a new laptop for my wife. It came with Windows 10 already installed. Several times Windows has assigned a temporary profile to her after she had booted the machine. I have been able to get Windows to recognize the old profile by signing out of the temporary profile, signing in with the Admin profile, signing out of that and signing in with her profile. I have several desktop/towers running Windows 10 and have never had this issue on them. I have a couple other laptops running Windows 10 and have had this problem on them. On the other laptops, I have lost the profile, in one case several times, and had to rebuild. I would really, really like to avoid that again.