My mother's laptop has a defective CD-ROM drive that won't read things properly. In an attempt to fix it, I ran a CD-cleaner through it. To test, I tried an ubuntu install.
The CD-ROM read the ubuntu CD well enough to boot into the installation process. I then proceeded to format the existing ext3 partitions and continue with the install. Unfortunately, the CD-ROM then conked out. Blanking the partition meant grub wouldn't work, making the machine dead.
It turns out there's three ways to repair the MBR with windows:
- boot from the setup disk and go to recovery console
- boot from floppies and go to recovery console
- use a diagnostic tool from within windows to restore a previously backed-up MBR
One and three were ruled out by not being able to boot either windows or the CD-ROM. That left two. Unfortunately, after what seemed like 15 minutes of floppy disk juggling (do I really need all that raid stuff loaded just to use the recovery console?) setup asked me to press 'R' for recovery console and promptly reboot the machine.
My next strategy was to try and get enough of linux on the ext3 partition, via floppy and net where possible, to put a new grub on.
Firstly, booting grub from floppy worked great. However I didn't want to make my mother learn arcane grub commands in order to boot properly. So I either needed to get grub on the partition, or setup a menu.lst on the floppy.
Whilst fiddling with the former option I tried booting from a debian Sarge DVD I'd made the other day. Strangely enough, it complained a lot less about the home-made DVD than the factory pressed ubuntu and windows CDs. I got sufficiently far through the install procedure to setup grub, which means windows now boots again.