can't mount hard disk after upgradind to of 9.10

[carvao]

hi all,
after upgrading to 9.10 i was asked to reboot the system and after that ubuntu couldn't mount the hard disk. any solution?

[carvao]

i began the installation process at night, when i was downloading the packages and i went to sleep. the next morning i finish the installation but apparently some problem occurred at night and when i reboot the system it wasn't mount my hard disk any more. i was using 9.04 but for some reason the grub is showing only 8.10 options. what should i do?
thanks