1- set your system to show hiddenfiles/unhide system files this will show the WINMAIL App (Microsoft keeps it hidden in the app folder)
2- Take ownership of the Dlls /DUI and WinMail App in both 86x and 64x Program folders by changing the owner from (installer to you)
3- copy your Vista 32bit version and 64bit version (they are available on the web also) to the folders and replace the files
4- copy msidcrl30.dll /msidcrl40.ll 32bit or 64bit depending on your system to the win/System32 folder
5- start the app according to your system 64bit (program folder) 32bit (program x86 folder)
NOTE: app will create a (Windows Mail) folder in Users/yourname/AppData/Local/Microsoft/.... If you want to have access to your folders, emails and accounts, copy your Windows Mail folder from your last version to that directory before starting the App. Otherwise it will create a new blank folder with just the basic INBOX/SENT/DELETE/DRAFT...and no accounts or data. If you no longer have access to your old version of windows with the App folders, the system MSIs and the Windows Mail folder you're out of luck as most of the Sites that posted them for download no longer do it.
This works for Win 7, Win8, Win8.1 ....should work for Win10. I have Vista, 7, 8 & 8.1 and Don't care for 10 anytime soon.