Try turning on Windows Firewall if it's off. I have read on different sites that some users have had issues with mail and windows updates when runnnig an AV solution with a built in firewall and Windows Firewal is turned off. Seems like the problems started after build 10586
Problem with reverting back is sometimes it can cause your account to be corrupt, possible data loss. I had reverted one of my machines from 10 to 8.1 using the Backup and Revcovery and had some issues afterwards. That is why now, I will create a system image. If I want to revert, I just pop in...
This is what I do. Go to Control Panel, select File History. Turn on File History if it's off. Then click on Run now to backup to your medium. If you are using an external drive, plug it in first and make sure that your drivers are installed. I also do a System Image Backup of my PC (bottom of...