Dropped/damaged HD - what are chances of data recovery?

PC got knocked off the desk, it was powered on but idle, now won't boot, HD not recognized. (It's a Seagate Barracuda 7200.9 SATA HD, has XP SP3). We'd be happy just to get the data back.
So, ...
We got an external USB enclosure to connect to a working pc. It works fine with a brand new HD. But with the dropped HD, the device isn't recognized, but the disk makes clicking noises as if trying to do something. Device Mgr shows a yellow icon, says the device is not prepared for removal or something like that. Pulled it out and in again, no difference.

Before giving up, - how likely is it that the data is recoverable - does the clicking noise suggest (merely) a mechanical part. We live in the sticks - 2 hours to the nearest repair shop. Should any competent repair shop be able to do this, or does it require special expertise?

p.s. I called Seagate's recovery service, they think they can probably recover - but would cost $1700 (if successful) - Yikes!

Any advice?

It's unlikely you can get it to work yourself, or with any basic tools. Seagate's data recovery is good - they could probably get the data, but you have to ask yourself whether the data is worth that much to you.

As for the freezer trick, it might work, but I wouldn't count on anything. Also, if something you do does get it working, immediately start copying the data off of it, and don't shut it down until you have everything you need, as there's no guarantee it would start again.

You can try something like GetDataBack, I've had some luck with it and they have a trial you can run to see if it works before buying it.

If the drive's showing up as unformatted it might help, if the device is in error status though, no software method's going to help.

The clicking noises often imply that it isn't spinning up. This makes normal (and cheap) recovery methods unlikely. Still, it could be worth a try.

i once had a drive that crapped out on me, but it had upwards of 8000 hours uptime. it made a clicking noise just like you describe, so i removed the cover and powered up the comp. The noise, it turns out, is the heads trying to read the disk, but can't. My main problem was to prevent the heads from smacking into the center spindle at a very high velocity. I never did fix it, but ended up completely destroying he drive by putting a fingerprint on the platter :0

No software will work since it's a mechanical problem.
Freezer trick won't work. It only helps on drives with gradually degrading media. Not this case.
If the drive was spinning when it fell most likely the heads are dead now.
If it was not spinning then it's the worst scenario - platters lost alignment...
Anyway, if you need to get your data you should get your drive into professional data recovery lab. And it's not gonna be cheap
Dropped drives are the most difficult in data recovery.

You can try inbuilt recovery tools but I am not sure it will recover your all data. Your hard disk is damaged physically that’s why now you need to take help of data recovery services. You can take help of Stellar Data Recovery. I take the help of this company when my hard disk was physically damaged. It is one of the best company who offers “No data No charges” policy.

More details can be found here : http://www.stellarinfo.com/