My upgrade have been interrupted with the following terminal warning. I tried to re-upgrade my system for many times, but the same thing kept occurring.
the last 4 lines in terminal (during upgrade):
Found Windows 7 (loader) on /dev/sda1 Skipping Windows 7 (loader) on Wubi system Found Windows Recovery Environment (loader) on dev/sda2 Skipping Windows Recovery Environment (loader) on Wubi system
after these lines, the upgrade is not continuing.