Live boot is the only way to go.

To fool the father.

Use windows daily to check school email, google for projects and resources, normal everyday stuff. Use office products (or what ever) to create documents. Set up spread sheets to track - gas usage, school schedule, whatever!

Modify these files every few days.

ineffect. Use the laptop as dear old dad wants you to.

NOW.

When you're off to surf pr0n, act out in an online chat room pretending to be a 15 year old cheerleader.... no wait that's me! Anyway when you head off to create acounts at hotmail, yahoo, facebook shut down your laptop and boot into whichever live cd you choose.

Unplug the cat 5 cable from the modem and plug it into your laptop. SURF AWAY!!!!! If you plan on doing illegal things, use tor - or what ever proxy your distro offers.

VERY IMPORTANT!

Once you're done surfing, turn off your laptop AND YOUR ROUTER AND YOUR MODEM!

Plug the cat 5 back into the router and IN THIS ORDER turn on your modem, wait 2 minutes then turn on your router.

No trace