2,5" HDD problem

XP Pro with SP1

Lately while trying to start up I got the message that XP could not find my product key (I've worked with this HD 60Gb and my XPPro for more than a year and done regularily Windows Updates). Funny that I still could login in safe mode which also wasn't possible after 2 times. The HD was partitioned in C,E,H and K. The XP being on the C partition. I was planning to put another XPPro on the HD and because H and K where to small to put a second XPPro on them, I tried to join them together with a boot tool from Partition Magic that could do the job from a discette. While this job was being performed I got some message about "crossreferenced files", I tried the repair and/or fix utility no good. I pulled the HD out of the notebook and left it for some weeks (well protected). Meanwhile I installed a new XP Pro on another 20Gb HD, and just recently bought a 2,5" HD external USB 2.0 case, the purpous was to retrieve data from the 60Gb HD. Now my operating system does not "see" this drive, in fact it doesn't see any partitions whatsoever although it sees that there is a FujitsuMHS60Gb under the "Hardware".
Any solutions ??