Fingerprint reader and "ON" button not working?

I have a refurbished latitude E4200 that came without user guides. I am told all the drivers are installed - but they may not be!

How can I ensure I have all the original Dell drivers?

And if I have them, how do I get the fingerprint reader to work - I have never used a fingerprint reader before, and do not what to do?

And how is that "ON" button supposed to be used - do I need to configure something? - at the moment if I put the computer to sleep (using teh START button menu) , it wakes up when I open the lid - but when it hibernates NOTHING wakes it up, and I have to reboot!