Boot Into Windows From External Drive

I have two ThinkPads T61. One went kaput but I was able to take the hard drive from the dead laptop and swap it with the hard drive in the functional T61 and had no problem booting to Windows from it. However, I'm left with the hard drive from the working laptop and no device to put it in. I obtained a ThinkPad T500 without a hard drive, pretty much identical to the T61, and mistakenly assumed that since I was able to swap out the two hard drives in the T61 models, all I'd need to do is pop in the displaced hard drive and thus be able to boot into Windows with it. Unfortunately I still have a homeless hard drive and no way to access it. I connected it to the T500 with a cable, hoping it would boot from USB (I did change the boot order in BIOS to do this), but it still booted from the hard drive of the laptop, which seems to indicate that the external drive is not a bootable device. I opened the folder of the external hard drive hoping I could save the docs on it to the installed hard drive, but there were few folders and files I recognized. In essence, useless.

Is there any way to be able to log into Windows from that external drive, thus giving me access to the same data I viewed when it was in the T61? Or an adapter of some sort? A cable? A tweak of the registry or BIOS? I obtained a hard drive of another T500, inspected it closely, and the drives of the T61 and the T500 are identical, except for the data on them. My first choice would be to be able to install the T61 drive into the T500 and be able boot into Windows. Barring that, I'd like to connect it to the T500 (or any other laptop) and boot from the T61 hard drive. I have a lot of information, programs, and files on that hard drive. Is my only option to obtain another T61?

If I'm confusing you, I apologize....I'm pretty confused myself!

Holy crap. This is Brilliant! I'd read about this but forgot about it. Long story short 'inherited' a box similar to mine, w/better chip & mobo but no way to use the best of each box. Thought I'd salvage a cooler, explore VirtualBox etc. and hope for the best.

This Paragon solution can really improve my situation. Now I can part out the one box and put that towards new - really new - hardware.

This is huge. Huge win. Thanks SIW2, much obliged as they say,

Mustachio

SIW2, I’ve already tried putting the T61 hard drive into the T500. It resulted in BSODS, lock ups, freezing. Tried two of the T61s and got the same results. I purchased an internal hard drive for the T500 and set it up successfully. Then I removed that hard drive and placed it into the T61. Another fail. I compared the two hard drive and I could see no differences whatsoever.

BTW, can someone tell me where I can locate an adapter that will fit into the optical drive, giving me extra USB ports? Two out of the three ports on my T61 are non-working and I’m finding I don’t want to use an external USB adapter that plugs into the one remaining USB port I have left. I found just such a device for a Dell Inspiron D600 but nothing seems to be available for Lenovo ThinkPads.