flush dns
Windows 10, 8.1, and 8
Navigate to the desktop. (From Home, tap or click the Desktop tile).
Right-click the Start button (the Windows logo in the lower-left).
Choose Command Prompt (Admin).
When asked whether to allow Command Prompt to make changes to your computer, select Yes.
Note: If you are asked for an administrative login, you will need to contact your system administrator.
Type "ipconfig /flushdns" and press Enter.
Type "ipconfig /registerdns" and press Enter.
Type "ipconfig /release" and press Enter.
Type "ipconfig /renew" and press Enter.
Type "netsh winsock reset" and press Enter.
Restart the computer.