Someone may have used a DISK MANAGER tool like Ezdrive, Maxblast to create the drive and it's only "bootable" to see the contents. Also, USB cases might not translate the HARD DISK GEOMETRY in the same way as the laptop did.
What I use in such cases is this under 4 buck adapter to slide it into a PC for data recover is -> http://www.geeks.com/details.asp?invtid=HD-108&cat=HDD
This way, I could boot that drive if need be to scrape off files or place it on the second IDE channel to see if it works.
-> In closing, the reason you are doing this is likely due to a crashed machine. There is no reason the files would survive. But we always hope.
Ok ive just taken a hd from a compaq armada notebook the hd is a seagate hd ive connected this drive to an external bay then plugged into pc with usb 2.0 computer picked up drive is also listed in device manager problem is it wont come up in my computer ive went to device manager and went to volumes / populate and it comes up as unreadable. I know that win98se is on the notebook hd and there is files i need to retrieve off this hd maybe theres a third party program that can look at the contents of this drive any help on this would be much appreciated!