I tried installing Ubuntu 12.04 from DVD disk (clean install). But it gets stuck on the loading/booting screen.
On pressing Esc, I get some errors as follows:
pwconv failed to change the mode of /etc/passwd- to 0600
And in the end this is shown, after which installation just gets stuck, I can do nothing except switching off the power source:
Starting crash report submission daemon [OK]
Dell Vostro 1440
Core i3 (2nd gen)
Intel HD Graphics
Currently I have Ubuntu 10.10 (Freshly Installed from http://old-releases.ubuntu.com/releases/10.10/) and wanted to upgrade to 12.04, but am unable to manually upgrade as authentication fails in update manager. Also, I am not able to download applications from Ubuntu software centre and it asks me to check my network/internet.