I’d suggest a three-pronged approach.
First, if your data is on a hard drive, and you think it’s still there after the crash, stop using the drive immediately! Turn off the computer and don’t do anything to it. Do not install any software to try to retrieve the data. In fact, leave the computer turned off until you can get it to a reputable data recovery company. Writing anything more to the drive can overwrite your deleted files and make them unrecoverable.
Second, contact a data recovery company. You want one that specializes in recovering data from hard drives (as opposed to flash drives or CDs) and has a good reputation for doing so. They’ll probably charge to get your data back, but that’s much cheaper than recreating it. Also, ask around at computer user groups and see if anyone has had their data recovered through an outfit they’d recommend.
Third, keep your backup disk offsite in a fireproof location. If you lose your office building in a fire, an on-site backup disk will be toast too. If you have an office safe whose contents are insured against theft, put the disk there; otherwise leave it at home.
Rescue Your Data
If you’ve lost data, you may be able to recover it, but it will take some effort. Here’s how.
Back up, back up, back up!
This is the single most important thing you can do to protect your salvagedata. Regularly backing up your hard drive is the difference between a minor setback and a major disaster.
If you have a disk with important data and you hear bad noises, turn the disk off immediately. Do not run any software to try to recover anything. If there are important files on the disk, copy them onto another disk right away.
You can often salvage one of these disks by putting it in a freezer overnight (wrap in a plastic bag to prevent condensation) and then running your favorite data recovery program directly after bringing it out of the freezer. The idea is that cold contracts thing, so if it’s just the heads that are stuck, they should come unstuck when it’s cold and then spring back into position when it warms up.
If that doesn’t work, try freezing the drive again, but this time when you take it out of the freezer hit it sharply with your hand a few times. I’ve heard some people say this works; I don’t know how or why.
The best way to salvage your data is to have a backup. And if you already have a backup, then you should check it. Put your old backup in the next room, close the door, and then try to recreate the same data disaster as before. Only this time, do it right by using multiple backup solutions. Backup online (to Dropbox or Google Drive) and on external hard drives or zip drives, preferably one from another brand. That will ensure you’re covered for both hardware and software failure.