Grub fails after kernel upgrade

I also tried this at the prompt:

linux /boot/vmlinuz-2.6.31-14-generic root=/dev/sda2 loop=/ubuntu/disks/root.disk ro
initrd /boot/initrd.img-2.6.31-14-generic
boot

...but there's no /dev/sda* (or /dev/hda*, for that matter)

^ I think that's partially cause I'm on a Lenovo (G450 laptop).

I can confirm this bug!
After having Ubuntu, (install from Wubi) running ok, I end up having to make some updates involving kernel updates, after restarting the computer I noticed that Grub was no longer available. I used an live CD to restore Grub. One week later I had one new kernel update and this time the problem was that I was unable to boot from the new kernel. So I kept using the older version.
Right now I made one more kernel update (many kernel updates recently) and after restarting the computer I had the normal options for Windows and Ubuntu, but after selecting Ubuntu I no longer have the usual GRUB screen with all the kernel options but just a grub terminal.

Grub version 1.97~beta4 (why beta?)

[Minimal BASH-like line editing is supported. For the first...
...

sh:grub> _

Something is really messed up.

I was looking for information on how to restore grub like I did last time (short memory) and found this bug report.

I'm using a COMPAQ Laptop and think that it is not a problem related with the machine. It is something that goes wrong after kernel updates or kernel upgrades.

Hope this post was useful.

one HD. having 2 ntfs partitions, wubi install of Ubuntu was made on the second partition

I really think this bug should be known as "Critical" for Wubi, even if it's about Grub.

The patch is here on comment #90 : https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/477104?comments=all

It looks like Wubi is not advised any more for beginners until Wubi installation is patched. Too bad because beginners are the target public for Wubi.

And every people who have tried Linux for the first time with this Wubi release will keep a really bad taste... (crash after the first update => go back to Windows)

Exactly same problem overhere! This is a critical issue (also for succesfully letting people getting to know Ubuntu via wubi installer)

Bug confirmed in three different 9.19 wubi installations:
* two after updating to 2.6.31-17, one over XP and another with Windows7
* one after updating to 2.6.31-19 over Windows7

Last one resolved using patch referenced in comment #5

I do thing that this bug should be categorized as critical: everyone applies updates, and all the wubi installed machines will fail in Ubuntu, and will be only used as windows pcs.

Same problem. Replacing wubildr with patched one did the trick.

   root@ubuntu:~# uname -a
   Linux ubuntu 2.6.31-20-generic #57-Ubuntu SMP Mon Feb 8 09:02:26 UTC 2010 x86_64 GNU/Linux

Booting nice and smoothly now.

It seems a number of people are upgrading to Linux Kernel 2.6.31-20 today, so this bug report will get some traffic (as well as my blog post, http://blog.rickyc.org/2010/02/26/wubi-kernel-upgrade-goes-to-shgrub-prompt/ ).

To fix this read my blog post above, or just follow the solution section at http://sourceforge.net/apps/mediawiki/bootinfoscript/index.php?title=Boot_Problems:Wubi_9.10&oldid=214 .