I started the update and went to sleep but I forgot to plugin AC adapter. When i woke up, laptop was off. I plugged in the AC cord and turned it on. Ubuntu boots and it is on 12.10 but may items are missing and neither gnome nor unity seem to work properly. It's also very slow and freezes sometimes. Is there a way to correct all those issues ? or revert back to 12.04 then re update to 12.10 without losing my data ?