How did u clone it?? did u take the master H.D plug it into the 2.5"->IDE converter and clone it using a desktop? did u use DOS clonning? or did u use ghost in window??
What i would do is connect the (master) laptop H.D to the IDE converter, then plug it into a desktop, use norton ghost boot disk to clone this (master) H.D to another H.D (formated with FAT32) as an image file. Then all u got to do is take another laptop hard drive plug it in and clone it from the image file to the laoptop H.D. That is if all of your 20 laptop are the same model, also you might want to reseal your OS before you ghost it to a image file. Of course there is another way, if your laptop have a dvd writer then all you have to do is put the ghost bootdisk in that laptop, put a blank DVD into the laptop dvd writer and you can save the image file to the DVD disc. After that just take the DVD disc and use it to ghost it to all other laptops.