As of today, my wubi installation of Ubuntu won't boot (goes straight to 'minimal bash-like interface) and I am unable to mount it when I boot straight to Ubuntu.

If I boot straight into Ubuntu (not using Wubi, not going via Windows), I am able to mount the Windows partition and see the Wubi partition there:

sudo mount -t ntfs /dev/sda5 /media/winxp

And from there I can see the wubi root disk:

/media/winxp/ubuntu/disks/root.disk

But if I try to mount this:

sudo mount -o loop /media/winxp/ubuntu/disks/root.disk /media/wubi

I get an error:

/media/winxp/ubuntu/disks/root.disk Input/Output Error

If I then try fsck:

sudo fsck /media/winxp/ubuntu/disks/root.disk

I get this: Input/Output Error while trying to open /media/winxp/ubuntu/disks/root.disk

The Superblock could not be read or does not describe a correct etx2 filesystem. If the device is valid and it really contains an ext2 filesystem (and not swap or ufs or something else), then the superblock is corrupt and you might want to try running e2fsk with an alternate superblock:

e2fsck -b 8193 <device

... this gives me the same result.

There is data on this partition that I really need to be able to access, so I can't delete and reinstall.

Any help much appreciated. Thanks.