Hello
You are not going to remove that USB HD till you are done copying right?
It will not hurt to just unplug the USB HD when copping is done.
Sometimes plugging in a USB device after PE is booted to the USB device may not be detected and installed right
Then I would check to make sure files have been copied
Reboot Laptop and reload
After you are done I would look at updating Your PE disk
It MAY have been faster to image Laptop HD
I like to have a complete image of a HD
Good luck
Snow...........