Wubi installtion with Error 15

[Kejing]

Yesterday, I install Ubuntu via Wubi under Windows XP SP3 En version. The Ubuntu was installed on a removal USB disk

When wubi asked me to reboot the system, then I followed the instruction. Then the system stuck with the following information

find --set-root --ignore-floppies /ubuntu/install/boot/grub/menu.lst

Error 15: File not found
Press any key to continue...

After pressing enter, I got another message

GRUBDOS 0.4.3 2008-4-22 Memory: 639k/1014M, CodeEnd: 0x41228

find /ubuntu/disks/boot/grub/menu.lst
find /ubuntu/install/boot/grub/menu.lst
find /menu.lst
find /boot/grub/menu.lst
find /grub/menu.lst
commandline
reoboot
halt

What am I supposed to do?

[tinybit]

press c to enter command line, at the grub prompt type these commands:

debug on
geometry (hd0)
geometry (hd1)
geometry (fd0)

This should list your partitions and filesystems in your machine.

If it can not list anything for your USB drive, then you may try to install a grub4dos with the build grub4dos-0.4.3-2008-06-12-geometry-tune-test-only.zip found at http://grub4dos.jot.com/

[ago]

https://wiki.ubuntu.com/WubiGuide#he...6abc67f608d742