They've put restrictions on what you can do on the laptop for a reason. Stop trying to circumvent the security settings. If you want to access things like Facebook, get your own laptop.
What you may not realise is that organisations like schools have had to put security in place on their IT equipment because the bulk of users of their equipment are dont care what they connect to, what they run on the equipment, or what they plug in to the equipment. This leaves the machines AND the network they connect to vulnerable to virus infection, or worse...left vulnerable to attack.
How happy would you be if you accessed whatever sites you wanted on your laptop, and then tomorrow your laptop was responsible for introducing the Conficker virus to your schools network which will cost thousands to clean up and fix? Thats money from tax payers pockets...my pocket included.
Sorry, rant over, but if you want to access something you cant on your schools laptop, use your own.