Comment 20 for bug 551721

My wife and I have identical HP(Dell) laptops (Compaq 8710p). We both dual boot XP/ubuntu. I upgraded 8.04->10.04 a number of months back, and all was relatively painless. We tried to do the same to hers and hit a bunch of upgrade problems (not obviously related to this bug) so I decided to "nuke it from orbit" and after backing up her home dir, installed from the current 10.04 iso, reformatting the existing ubuntu partition. Neither of us had any problems like this bug describes under 8.04, and I haven't seen this problem under 10.04 on my machine.

The install went fine, but first thing I tested was booting in to windows to make sure I hadn't messed anything up there. All looked good, restarted, and BAM, hit the "no module" message. It's possible that she has different windows software (Mcaffee seems likely culprit) that is tickling this bug. Also, it looks like back when I upgraded, I still had legacy grub, not grub-pc. As others have said, the smaller footprint may be avoiding the problem for me. My system has never hit this, booting between windows and ubuntu.

Work around that seems to have worked for me:

Following instructions here:

http://sourceforge.net/apps/mediawiki/bootinfoscript/index.php?title=Boot_Problems:Windows_Writes_To_MBR

and here:

http://ubuntuforums.org/showpost.php?p=8068512&postcount=10

I removed grub-pc, installed classic grub, re-installed grub-pc in a "chain-loader" configuration, and removed the Mcafee software from her XP machine, and that combo seems to be working. I'm hesitant to fully install the new grub to the MBR until this issue is fully understood and fixed.

In summation:
There seems to exist various bits of windows software which write to the MBR in such a way as to corrupt the current grub2 style of doing things that don't seem to bother the previous grub install. Removing these from Windows seems to fix the problem, but just sets you up to be bit by it again later. Previous grub seems to avoid these problems, and seems to be the best work-around so far. Looks like it can chain-boot grub2 safely, _so far_.

This isn't Ubuntu or the grub/grub2 maintainers _fault_, but it is their _problem_. Lots of us are dual-boot various flavors of windows and Linux, and if this wasn't a problem with the earlier grub (even with windows misbehaving and writing where it shouldn't) it _needs_ to continue working with grub2.

Staying with older grub and/or removing windows apps are not sustainable solutions long term.
Hope that info helps someone.