"Bad Checksum" problems can be overcome in most cases by changing the download server (site) as follows:
- Do not click "Search for Updates" again.
- Using the pull-down site selection menu (between the "Search for Updates" and "Download Updates" buttons) select another server.
- After changing the download server click "Download Updates" again.
- If you get another "Bad Checksum", repeated Steps 2 & 3 (using a 3rd or 4th server if necessary) until all updates are received.