Though things get much more difficult if you want to try and preserve the data on the drive.
The first thing you need to do, is figure out if the drive suffered some kind of mechanical failure, or if the operating system just got corrupted and will not boot. You're almost certainly looking at a reinstall of the OS either way, but if there's no mechanical failure, you have a decent chance of being able to recover the data off the drive. Probably have to use something like a Knoppix Linux boot CD, but that isn't overly difficult.
If it suffered from a mechanical failure, unless the data on the drive is worth more than about 2000USD, consider it lost. That's about how much it would cost to use professional recovery services, and there's no guarantee they'll be able to recover anything. You'll just need to get a new drive and start over.
Whatever the case, hopefully your wife was good about keeping backups. Otherwise, consider it a very painful lesson to learn about the importance of backups.