I have been using ADE edition 4.5.1 for some time on a Windows 10 pc, to download library books. which arrive in a .acsm file. This used to be automatically opened by ADE and the epub file downloaded. Now the default prograqmme has been changed to ADEAutoUpdater, which doesn't open the file, and the default can't be changed to ADE, because it doesn't appear in the list of available apps. What is ADEAutoUpdater, and how cn I change the default programme back to ADE?