Most reason is because the flash memory or CD is containing viruses. So the best solution is to make format for flash memory or CD by office scan in the bottom of the page.

• Check your device if it's connected to the network by the network icon on the bottom of the screen.
• If your device is connected to the network but still can't connect to the internet, then check your proxy in the Internet Explorer Options. Follow these steps:
• In the Internet Explorer, press "Tools" and then "Internet Option".
• Press on Connection Tap.
• Press on LAN settings.
• If you are connected inside KSU network, then:
• Put a check in "Use a proxy server".
• Write on the "Address" field "proxy.ksu.edu.sa".
• Write on the "Port" field "8080".
• Click Ok on the "Local Area Network" and "Internet Options".
• If your device is connected outside of KSU Network:
• Remove the check from "Use a proxy server" in the Lan Area Network.
• Click Ok on the "Local Area Network" and "Internet Options".