I had installed the Windows 10 Mobile preview on my Nokia Lumia 620 and now i'm using the Windows Phone Recovery Tool to downgrade to WP 8.1 but, the recovery tool shows "check proxy setting and come back again". How do i fix it?? Please Help
Sounds like a firewall issue rather than the application itself. Try disabling your antivirus/firewall and try again to see what happens.
If you are using proxy to connect internet please disable that, refer to the steps below to disable proxy:
Press “Windows Key” + “R”. Type “inetcpl.cpl”. Go to Connection. Click on LAN Settings. Check the box which says automatically detect settings. Uncheck the box under Proxy server.
Disable antivirus software and firewall
If you are using any 3rd party antivirus or firewall, I suggest you to disable it.
Follow the steps provided in the article below: