Unable to fetch Ubuntu Archives 404 Not found [IP: 91.189.92.201 80]

If you are unable to fetch  archives in Ubuntu, there may be few of the reasons:

1. Either your dns lookup failed,
2. Or your archives lookup address got changed.

I will highlight both of the possibilities and represent you the solutions.

If your dns lookup failed, you can follow the below steps:

• First, take the backup of the /etc/resolv.conf file by running the following command
  $ sudo cp /etc/resolv.conf /etc/resolv.conf.bkp


• Add the following entries in the original /etc/resolv.conf file
  nameserver 8.8.8.8 nameserver 8.8.4.4


• Save the file and restart the network using the following command
  $ sudo /etc/init.d/networking restart


• It may be possible that your ubuntu gets hanged as happened to mine.There is no need to panic, you can run the following command to get your system working Press Ctrl+Alt+F1 You will enter into command line mode.There it may ask you for your username and password. Provide it and run the following command: $ sudo reboot Your system will restart... Starting working :)

Or, your archive address got changed ( 404 Not Found [IP: 91.189.92.201 80] )

Again if you are getting the same error while fetching archives, then that means your archive has changed.
And the best way to determine is check whether you are getting the following error

Err [your archive address] 404 Not Found [IP: 91.189.92.201 80]  <br> E: Some index files failed to download. They have been ignored, or old ones used

If this is the case follow the steps below:

• First take the backup of the /etc/apt/sources.list by running the following command
  $ sudo cp /etc/apt/sources.list /etc/apt/sources.list.bkp


• Change the name from the archive.ubuntu.com to old-releases.ubuntu.com $ sudo gedit /etc/apt/sources.list Replace the name archive.ubuntu.com with old-releases.ubuntu.com

Thats it.. .Definitely your update will work now ....