ipconfig /release, ipconfig /renew

When everything else is not working for you to connect to the internet, try these Windows command line utility tools - ipconfig /release and ipconfig /renew.

The Internet Protocol Configuration (IPConfig) in Microsoft Windows is a console application that displays all current TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol DHCP and Domain Name System DNS settings (source).

One time I woke up early in the morning, I noticed that I was not able to connect to the internet. I cleared the private data cache of my browser, used CCleaner to clean all crap and unwanted computer files. Unfortunately, nothing seems to work. Then I thought of using these ipconfig tools and presto! my internet is back.

Here's how to do it.

For Windows XP/2000 and NT:

1. Open command prompt; go to Start Menu > Run and type "cmd" (without the quotes).

2. Type "ipconfig /release" to release the IP address for the specified adapter. Note that there is a space between those lines.

3. Next, type "ipconfig /renew" to renew the IP address for the specified adapter.

Other IPConfig options for Windows XP/2000 and NT are:
  • "ipconfig /all" - To display full configuration information
  • "ipconfig /flushdns" - To purge the DNS Resolver cache
  • "ipconfig /registerdns" - To refresh all DHCP leases and re-register DNS names
  • "ipconfig /displaydns" - To display the contents of the DNS Resolver Cache
  • "ipconfig /showclassid" - To display all the DHCP class IDs allowed for adapter
  • "ipconfig /setclassid" - To modify the dhcp class id
For Windows Vista:

1. Type "cmd" in the Search Box under the Vista Start Menu and press Ctrl + Shift + Enter in order to launch the command prompt administrative privileges.

2. To release both IPv4 and IPv6 addresses, type "ipconfig /release" and then when done type "ipconfig /release6"

3. To renew both IPv4 and IPv6 addresses, type "ipconfig /renew" and then when done type "ipconfig /renew6"

Other options for IPConfig in Vista:
  • "/?" - Full configuration
  • "/allcompartments" - All compartments
  • "flushdns" - To purge the DNS resolver cache
  • "registerdns" - To refresh DHCP leases and reregister DNS names
  • "displaydns" - To reveal the contents of the DNS resolver cache
  • "showclassid" - To display the DHCP class IDs for the adapter
  • "setclassid" - To modify the DHCP class IDs for the adapter
If you have a similar experience as written above, or this tip helped you, please don't forget to leave a comment or two.