I tried to move my WUBI installation according to this: Move WUBI installation of Ubuntu to a different partition in Windows. But when I boot Ubuntu, it can't find the root.disk file. Is there any way to restore it? I have Ubuntu 12.10. Please help.
Do you have a copy of the original root.disk in a safe place? If not restore the original file from Windows backup and keep in a safe place.
One more step
See http://askubuntu.com/a/55029/14916 for details (Thanks to bcbc for pointing out this part.) The following is taken from that answer:
Assuming Ubuntu is being moved from
Delete the line -
This is a one-time override - hit Ctrl+X to boot, and make sure you run
PS: There may be some variations.
Hope this helps