Windows Live Mail – Fails to Initiate Shared Canvas

I help one of my neighbours with his PC and software.  (He calls me 'His 5 minute man' for he says have you got 5 minutes!  Often takes far longer than this.  Particularly this problem.  Which I have seen on the Forum.  One solution is to roll back to a previous restore point.  Looking at the restore points on his PC which one do I choose?  When was this update to Windows Live Mail issued? If I knew the date of the update I could choose a prior restore date point.  (And then re-install any critical patches.  I believe the Windows Live Mail update is completly independant of the Windows Patch updates.  His Windows Live Mail is Build 154.3555.0308.  Is this the updated version that has the bug in it??  If not I will have to un-install Windows Live Mail and re-install, assuming that the download will not contain the bug?  If I have to un-install Live Mail I will need to back up the Mailbox or Mailboxes, but I am not familiar where these are.  (Personally I use Outlook which is a much more professional product and I know how to back up and even repair the mailboxes for this application).  His Dell machine is running Windows 7 home (64bit).   This I have to say is really anoying, for a home user like my neighbour he would have no idea how to fix it.  And even I who am pretty IT literate am struggling with.  I could ask how on earth did Microsoft achieve such a bud in an update to this widely used program?  But more important how can I fix my neighbours machine quickly and easily.  So I would be greatful for some help, even though this has been on the Forum already.  Thanks