A rescue CD allows you to boot a linux environment from CD. From there, you can mount the local hard drives and do any required work to fix the boot record, etc.
Here's a good rescue CD: http://www.tux.org/pub/people/kent-robotti/looplinux/rip/
I got the Linux / FreeBSD combined one, it's very nice and only 38MB. 2.6 kernel (so it supports SATA) and has chroot.
On CS application server (Asimov)
This is also available at the CS application server: \\asimov.cscf.uwaterloo.ca\rawiso\linux_utils\RIP-11.3.fbsd.iso
Version 12.4 has chntpw on it - one less CD to carry around, hurray. There's a couple of versions of 14.x - one for Linux with GRUB, another with the old FreeBSD style on it.
If you're setting up a machine using the PXE boot option, you can also run the Rescue Disk there. Use the RIP
image (currently RIP14_9)
updated -- MikePatterson
- 13 Apr 2006