I figured out why you might be having issues upgraded the operating system. I spoke to our engineers, and unfortunately, with our Dell image there are proprietary drivers and repositories. This will cause an issue and prevent you from upgrading to 15.04/15.10.
If you want to see how the system will operate in 15.10 without installing it first, you can run the ‘live cd’ on the system and see how it works with the touch pad. That way you can decide whether or not you would like to upgrade.
Here is the link for the download:
http://www.ubuntu.com/download/desktop
In order to use this, you will need to boot from a flash drive.
- Power on the system and press F12