I also have a Dell Inspiron 600 that got the HDD error. it went out about 6 months ago, and after putting in a new hd with no luck, I called Dell. I was told by them that the mainboard was bad, apparently its the hdd controller, a part on the mb. Dell quoted me like 600 or something like that to fix it, but i haggled them down to about 300 including everything. I ultimately decided against it,a nd just bought a new laptop.
As of now, I am actually posting this on the Dell. I pulled it out today, because i got the idea to use a linux live-cd to try to get it to boot and see if i could recover some stuff. I had already tried an external enclosure through usb, and an adapter for the notebook hdd to plug into an IDE cable, both with no luck.
So right now the computer runs, but does not see the HDD. I'm assuming that Dell was right about the problem. Also, I called a local notebook repair shop and they gave me the same diagnosis.
So I hope that helps some of you. BTW, even though its the hdd controller, it seems that the data on the hdd itself is corrupted or something, because i could not read it anywhere else, and a new hdd in the Dell didn't read either, so i guess both the part, and the hdd are toast.
Now that i am back on the Dell, i miss this thing. this keyboard is so much better and the antiglare screen is great compared to my newer Acer.
Well, Hope that helps. Post up something if anyone has any luck getting info off the drive later, I need to figure something out, or i might just freeze it and try.