If you found this thread because you are stuck with an unbootable machine like I was, here is what I did to fix it:
Step 1: Restore your MBR:
## boot ubuntu live from CD/USB then do the following:
ALT-F2 gnome-terminal
sudo mount /dev/sda6 /mnt
<- sda6 on my box. YMMV.
sudo mount --bind /dev /mnt/dev
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys
sudo chroot /mnt
sudo grub-mkconfig -o /boot/grub/grub.cfg
sudo grub-install /dev/sda
ctrl-d
sudo umount /mnt/dev
sudo umount /mnt/proc
sudo umount /mnt/sys
sudo umount /mnt
Step 2: Boot into Windows, run services.msc, and disable the "PC Angel" service.
(This was the root cause on my HP laptop, some people have suggested there are other programs which can cause this problem).
Step 3: Boot computer and repeat Step 1 since booting into Windows on Step 2 re-trashed your MBR.
I had the same problem with Beta 1 and Beta 2. Please see:
https:/ /bugs.launchpad .net/ubuntu/ +source/ grub2/+ bug/441941? comments= all
If you found this thread because you are stuck with an unbootable machine like I was, here is what I did to fix it:
Step 1: Restore your MBR:
## boot ubuntu live from CD/USB then do the following:
ALT-F2 gnome-terminal
sudo mount /dev/sda6 /mnt
<- sda6 on my box. YMMV.
sudo mount --bind /dev /mnt/dev
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys
sudo chroot /mnt
sudo grub-mkconfig -o /boot/grub/grub.cfg
sudo grub-install /dev/sda
ctrl-d
sudo umount /mnt/dev
sudo umount /mnt/proc
sudo umount /mnt/sys
sudo umount /mnt
Step 2: Boot into Windows, run services.msc, and disable the "PC Angel" service.
(This was the root cause on my HP laptop, some people have suggested there are other programs which can cause this problem).
Step 3: Boot computer and repeat Step 1 since booting into Windows on Step 2 re-trashed your MBR.