Will the 40GB drive format using Disk Management? (Start>[Rightclick on My Computer]>Manage>[Opens MMC]>Disk Management) If the drive shows up you should be able to format it. If not you may be screwed.

The only method I can think of for recovering your data is to get hold of an identical drive and transfer the platter(s) over. It's a risky procedure but you may think its worth it depending on how imporatnt the data is to you. Alternatively you could send the drive off and have the procedure done profesionally. Of course this would be followed by a rather large hole in your wallet, but again, how important is the data to you?

One final thought: I know it sounds odd but I've heard that putting the drive in the freezer (?) overnight may help. I've seen stories (read: rumors) that it might get the drive working for a little whilehust so you can recover the data from it. Make sure it's fully defrosted before connecting it to anything! Have a look into it and see what you think about it.

EDIT: Take a read of this: http://geeksaresexy.blogspot.com/2006/01...-data.html