I have Windows Live Mail as my email client on my desktop PC.  Lately, Windows Live mail has become extremely slow in starting and I want to Refresh my PC.  However, before doing so, how do I backup all my email messages particularly messages in the INBOX and SENT folders of each email account.  I have several email accounts both POP and Imap. 

I understand that, after a Refresh, all email messages would be deleted.  How then do I backup all my email folders and then, after the Refresh, how do I restore the messages?  Can someone please explain to me in non-technical terms?

It appears the problem could not be due to a virus as I have run three anti-virus programs, including Windows Defender, Malwarebytes and Microsoft Safety Scanner, but there were no threats detected.  I even uninstalled Windows Live Mail and then re-installed it but that made no difference whatsoever.  I takes almost eight minutes before Windows Live Mail starts.  Before Windows Live Mail would start in just four seconds.  Something is hampering the start.