I have Ubuntu 12.04 installed through Wubi on my laptop. For some reason when i click on Ubuntu on start up (when you have to either select windows or Ubuntu) I get the following screen, the grub cursor keeps flashing.
Gnu grub version 1.99-21 Ubuntu 3.4
Minimal bash-like line editing is supported. For the first word, tab lists possible
command completions. Anywhere else tab lists possible device or file completions.
grub>
Could you tell me what I can do to fix this problem and to start Ubuntu normally?
Best Answer
Sometimes the
root.disk
, the virtual partition that Wubi uses to boot, gets corrupted. This is a file that lives in the\ubuntu\disks\
directory. If Grub (insidewubildr
) cannot mount theroot.disk
, it cannot show the grub menu (which is stored on theroot.disk
) and then it just drops you to a grub prompt to await further instruction.There is nothing you can do from the grub prompt until you've figured out the problem with the
root.disk
and, odds are, there isNTFS
corruption. It's fairly common, for example, if you've performed a hard shutdown or reboot. In some cases, the reason isn't clear.What you need to do is to run
chkdsk /f
(or/r
) from Windows on the drive you installed Wubi. If you installed on theC:\
drive this will require a full restart.To run
chkdsk
on Windows 7 (the first checkbox corresponds tochkdsk /f
and the second tochkdsk /r
:If prompted, restart the computer and boot into Windows to complete the
chkdsk
making sure not to 'Hit a key' to abort it.After that, check the
ubuntu\disks\
directory to make sure theroot.disk
is still there. In some cases, theubuntu\disks\
directory itself is no longer present. If either are missing, you need to look for them aschkdsk
will often recover corrupted files/directories to hidden folders named\found.000
,\found.001
etc. These are hidden and protected OS directories by default (Windows 7) so they won't show up in Explorer. I find it easiest just to use the Command prompt.To do this, right-click on
CMD.EXE
and select "Run as administrator". Change to the drive the\ubuntu
directory is located on, and search for the hidden\found.???
directories.e.g. if the
root.disk
is missing, you're looking for a file >5GB
in size. If you know what size your install was it helps. In this case, it's15GB
If the whole
\ubuntu\disks
directory is missing, you're looking for a directory nameddir0000.chk
, and inside that you'll find the correctly namedroot.disk
andswap.disk
, so you can just move the directory back in place:Recovery isn't guaranteed in all cases depending on the extent of corruption. Note that the
root.disk
may be correctly in place before runningchkdsk
and then be removed after running it.Reference: http://ubuntu-with-wubi.blogspot.ca/2011/08/missing-rootdisk.html