Expired IP addresses or other issues with a computer's current IP address lease are often the reason for network connectivity issues. When you type "ipconfig /renew" into the command line, that command orders your DHCP client to renegotiate an IP address lease with the DHCP server on your router.
This will either renew your current local IP address with the router or get your computer a new local IP address if the router hasn't already re-assigned the current address.
The DNS (Domain Name System) cache contains all the information needed to convert a domain name into it's IP address which is used to request information from the server. If you are having connectivity problems (disconnection or lag) clearing out this cache (called 'Flushing') can help resolve the issue or improve your connection.
1) Press the Windows Key (the key on the left side of the spacebar, between ctrl and alt
2) Type cmd
3) Right-click the Command prompt shortcut and select "Run as Administrator" from the drop down menu. You should now see a black window with white letters.
4)Type ipconfig /release in the command prompt.
5) Press [Enter]
6) Type ipconfig /renew in the command prompt.
7) Press [Enter]
8) Type ipconfig /flushdns in the command prompt
9) Press [Enter]
10) Close the command prompt and attempt to make a connection.