itunes 12.2.1.16, win7: ipod not syncing, unable to play video

In Summary, itunes will not sync with either of two ipod classics and i cannot play any of my videos in itunes ("video playback is not supported on this computer". Here's what I've done:

1. Received prompt to install 12.2.1
2. Backed up all files, then clicked “OK”
3. Received the following error messages:
   1. itunes has an invalid signature it will not be installed
   2. Error occurred while installing the updates. If the problem persists, choose Tools->download only and try reinstalling manually.
4. Attempted to install update again…
5. Received message “your software has been successfully installed”
6. closed & re-launched iTunes
7. Connected iPod
8. IPod showed connected, syncing, then OK to disconnect but would not sync
9. Clicked on iPod icon in iTunes, then on “sync” button
10. Received message “the iPod XX cannot be synced because it cannot be found”
11. Restarted PC
12. Launched iTunes
13. Connected iPod
    1. IPod showed connected, syncing, then OK to disconnect but did not sync
    2. I click on the iPod icon in iTunes, the “sync” button is unavailable
    3. ITunes then shows “ the iPod cannot be synced because it cannot be found”
14. Restarted PC
15. Launched iTunes

    Help->About -> shows 12.2.1.16

16. Connected iPod
    1. IPod showed connected, syncing, ejecting, ok to disconnect
    2. I click on the iPod icon in iTunes, the “sync” button is unavailable
    3. ITunes then shows “ the iPod cannot be synced because it cannot be found”
17. Uninstalled:
    1. ITunes
    2. Apple software update
    3. Apple mobile support
    4. Bonjour
    5. Apple application support
18. Restarted PC (PC restarted OK this time)
19. Downloaded & Installed iTunes 12.2.1.16
20. Launched iTunes

    Help->About -> shows 12.2.1.16

21. Connected iPod
    1. IPod showed connected, syncing, ejecting & ok to disconnect
    2. I click on the iPod icon in iTunes, then the “sync” button
    3. ITunes then shows “ the iPod cannot be synced because it cannot be found”
22. reset ipod (via center button & menu button)
23. connected ipod with itunes running

a. itunes does not recognize the ipod, but windows does

Thanks in advance for any suggestions.