Windows 7 with missing WldCore.dll upgrading to Windows 10

I am a very novice user with an old windows 7 computer & Windows Live Mail 2012 - with missing WLDCore.dll.  I know Windows Live Mail 2012 (Windows Essentials) is not now supported so the WLDCore.dll can't be repaired.  There also appear to be performance issues on my computer but to repair these I have to subscribe.    I have decided to buy a Windows 10 and, hopefully, transfer all my files from my backup discs.   If I use this method to transfer my files will the discs be corrupted because of the missing WLDCore.dll?   Will much appreciate any help.