Can't start just after upgrade to 9.10

I have 9.10 LIVE CD. But I upgrade my 9.04 to 9.10 via update manager yesterday.
When upgrade completes, I restart my PC and then in log screen.. I select my user name and give password... Then a white screen comes and nothing happens.. i can move the mouse pointer upon white screen..

N.B. I also install Kubuntu and Xubuntu desktop 3 months ago via terminal and they worked fine till yesterday. So when i restart and select Xfce session from logon screen, then Xubuntu starts... but both KDE and Xfce sessions are too too too slow...

I want a solution... Is there a way to recover corrupted files from my 9.10 LiveCD? Or some commands??

I try FailSafe GNOME session... but same complete white screen..

Thanks in advance.