I installed Windows 10 64 bit on top of Windows 8.  A day or two later I tried to open windows live mail but received a message that Wldcore.dll could not be found, though it was in the windows mail folder. In the process of installing Windows Essentials again to correct this error I deleted the folders holding all of my previous email messages in the Mail folders.  Is this previous mail irrecoverable or is there a backup of these deleted files somewhere still on the system?