A  few weeks ago I upgraded from Windows 7 to Windows 10.  Did not like Windows 10 (like many others apparently) so went back to Windows 7.  Suddenly in Windows Live Mail several thousand "Deleted" emails appeared, along with some hundreds of "Junk" emails.

When trying to get rid of these all I get (apart from the odd one or two) is a pop up message saying "an unknown error has occurred".

I have noticed that very, very many people have the same problem and several solutions have been suggested by forum members.  None have worked for me unfortunately.   Unless I have missed something somewhere in the welter of information, there does not seem to be ANY USEFUL COMMENT BY MICROSOFT.  If Microsoft are reading this - CAN THEY PLEASE PROVIDE A SOLUTION?!!

Many thanks

John Scott