Once upon a time, Chris Murphy lists@colorremedies.com said:
If the head has been stripped, the driver is wrong sized for the screw. An exactly right sized driver with moderate pressure will unstick a tight screw so long as it isn't actually glued. And in that case with even more pressure it should still crack the glue with less than Herculean effort.
My Thinkpads have thread-lock on all screws, so that may explain why it is so difficult to break the screw free.