This is what I had today. After some two weeks long holidays, my Ubuntu distrib installed with WUBI refused to start. This is the solution I found to get back my files :
sudo fdisk -l
sudo mkdir /win
sudo mount /dev/sdxy /win
sudo mkdir /vdisk
sudo mount -o loop /win/ubuntu/disks/root.disk /vdisk
(Source : http://neosmart.net/forums/showthread.php?t=5004)
sudo fdisk -l
sudo mkdir /win
sudo mount /dev/sdxy /win
sudo mkdir /vdisk
sudo mount -o loop /win/ubuntu/disks/root.disk /vdisk
(Source : http://neosmart.net/forums/showthread.php?t=5004)