I bring up the software update, loads the list of software, and then it comes up with the update for Unbutu 15:04, I need to have 14:10 first before I can upgrade to 15:04. Tried to update in the Terminal, this is what I got. (do-release-upgrade)
"Checking for a new Ubuntu release
Get:1 Upgrade tool signature [198 B]
Get:2 Upgrade tool [1,221 kB]
Fetched 1,221 kB in 0s (0 B/s)
authenticate 'vivid.tar.gz' against 'vivid.tar.gz.gpg'
extracting 'vivid.tar.gz'
[sudo] password for mrkc:
Reading cache
Checking package manager
Can not upgrade
An upgrade from 'trusty' to 'vivid' is not supported with this tool."
Turns out that this upgrade to 15.04 from Ubuntu may not be an LTS (Long-Term Support) version. I will be waiting for the new LTS version 15.04 to show up in the software upgrader before I upgrading. Thank you for your help!