I have been using Ubuntu 11.10 along side Windows 7 for several weeks with only small issues, (rare freeze ups, mouse randomly stops working until reboot) But today everything froze, I waited several minutes with no response from my computer and after I tried everything else I just had to do a hard shut down. After I turned my computer back on and chose Ubuntu I got a the GRUB screen. I typed "boot" and it came back "error not kernel found". The only other thing out of the ordinary that happened with the computer lately is Windows installing some updates, and I had installed Tor on each OS.
Is there a way I can fix this aside from re-installing Ubuntu?
I searched through some other forums which said something about going into recovery mode from that screen, but I could not enter any command to get to recovery mode.