The odds are very high that the drive is not usable. The odds are good it's dead and you won't get anything off it.
If you weren't doing backups and you truly need the data there are services that have a decent chance of getting your data back. They are normally quite pricey, though--success probably means a 4-figure bill.
Those of us used to working on our equipment would have no problem putting in a new drive. Reinstalling could be problematic if you don't have restore disks for your machine, or if you have one of these setups that uses a hidden partition to hold the restore data.
If you're reasonably handy with tools you can Google your machine and find out how to swap the drive on it. (Unfortunately, they can be hidden, having directions helps. If you do it without directions, do *NOT* mess with any fans--there is thermal grease under them that's one-shot.)
If it's localized damage the boot CD will at least let you get your data off. If the drive failed (and they have a habit of totally failing without any warning) the boot CD won't do squat. See if the BIOS admits the drive is there.