|If you have a system state backup on your external drive then all you need to do is restore it. If it is just file backups then you will need to call the manufacture of your laptop, give them the serial number off the bottom and they can tell you what the key was.|
Personally, I wish they would simply put protective plastic tape over the labels when they stick the stickers on the laptops. We have the same problem, so I tape my laptops when we buy any. If I can do it why can't the manufactures?