After the download and during the install it asked if I would accept Microsoft conditions regarding fonts(?), and an was presented but would not accept any decision and just hung there.
Tried everything in my book (still a relative newbie) but it just remained effectively frozen, so I resorted to the ultimate sin and hit the reboot button! Since then it will not reboot other than to the point of presenting the Linux options for start-up. There's a message saying waiting for network to start whilst showing the purple screen and Kubuntu 11.04 but it never progresses any further.
I would either like to revert to a fully functioning 11.04, and not have my application software and files removed or corrupted or, if I can be persuaded, to upgrade to 11.10.