[i]I simply cannot lose some of the files that were on my external[/i]
You certainly shouldn't be using something which can completely destroy whatever it is you have on that drive.
As you say that this Data is [b]Important[/b] you should send it to someone who knows what it is that they are doing and pay the price of a Professional Recovery. The more that you unsuccessfully mess with the drive now the more expensive that recovery is going to be and the less likely it is to be successful.
According to Gibson Research Corporation the makers of Spinrite [i]The best way to learn what SpinRite 6.0 can do for you is to click the
PLAY button below to watch this fun, interesting and fact-filled video: [/i] Here
http://www.grc.com/sr/themovie.htm
Not really sure what is different with SP6 from the earlier versions because it's not something that I personally use and it's never something I would touch for anything [b]Important.[/b]
But with any Data Recovery you never make any changes tot he Affected Drive as that should never be touched just read from and the data saved elsewhere, that way if whatever you are trying doesn't work you have not done any damage tot he drive which is going to make it Harder/More Expensive to recover data.
Also if you understand Hardware as well as you say you do you would know that External Drives are only ever for [b]part time[/b] use and should never be relied upon as any form of Secure Backup let alone Primary Data Storage. You would never use something like that unless it's in a Vibrational Suppressed Enclosure which is actively cooled and even then you would know that the drive in it is going to have a shorter life expediently and be unreliable at best for [b]Long Term Storage.[/b]
NAS type enclosures are OK but the small external cases are just downright dangerous and they are way too unreliable to be used for anything short of Part Time Use when there is no possibility of anything happening to the drive and they should always be used with Desktops never a NB or NetBook.
Then there is the simple fact that they very rarely get dismounted correctly and have their Partition Tables Corrupted so they should only be used as a [b]Last Resort[/b] and even then never be relied upon to actually work. Those things give computing a very bad name as people expect them to be reliable which they simply can not be.
Anyway as said above if this is [b]Really Important Data[/b] you should now pack up the drive and send it to your preferred Data Recovery Specialist before you completely ruin any chance of recovering the data. If you must use a Software Option always save any data to another location that is most defiantly on another drive or you run the risk of hopelessly overwriting the data that you want to recover. When that happens you need to have a Forensic Recovery performed and the only places that I know who are capable of doing work like that do it for the Legal System Recovering Data of suspected Kiddy Fiddlers and the Big End of Town Corporate Crime Types. Not sure just how much one of those recoveries costs but it most certainly destroys the drive as they remove the platters coat them with some Green Goup and then read whatever directly off the platters.
However I wouldn't expect any change out of a Million $ if not considerably more.
I've personally not found anyone willing to pay that much for a recovery and it's only the Legal System backed by Big Government who follow this path for the really [b]Bad People.[/b]
Col