OK, for windows 10 you might have to do a little leg work, but if you look in:
C:\Users\[user id]\AppData\Local\Packages\Microsoft.MicrosoftSolitaireCollection_[probably variable]\LocalState\UserData\Guest\Statistic, you will find a file called: Statistic.ark.
Delete or rename this file and restart solitaire:
Assumptions:
1. You have decided NOT to participate in the game sharing ability for Microsoft
2. You have access to your system files (AppData is a hidden system folder)