I am running ubuntu 14.04 lts from a dvd.I am prompted to enter login and password.I tried ubuntu.guest etc.., but of no use Please guide me how to proceed. Regards, Dr Srikanth 918801245435
Sounds like you have an incomplete download of the .iso or the burn went wrong.
https://help.ubuntu.com/community/UbuntuHashes - This page contains all of the md5 hashes for the different versions of Ubuntu. Just look for the version you downloaded and see what the hash should be
https://help.ubuntu.com/community/HowToMD5SUM - Page shows how to check the iso using different operating systems. If the hash matches up, there is no problem with the iso file so that means something went wrong with the burn.
If you don't want to go through the trouble of checking, just download again (I would suggest using torrent) and make sure it finishes. Then burn at the slowest speed possible. Or if you have a usb drive and a bios that supports, just use that instead.
Edit: I forgot to mention. The reason I say this is you should not be prompted to log in.