Can’t delete e-mails in windows live mail

after I up dated to Microsoft 10 and then uninstalled it and went back to windows 7, I can't delete my e-mails

the pop up says:   windows live mail

                             an unknown error has occurred     then a pop up says: canceling     and nothing happens .

also when I try to delete my deleted e-mails it says : are you sure you want to send     and I click yes and nothing happens.

                                                                                     these to the recycle bin