Linux Mint 7 Gloria - Some Help Needed!?

I recently installed Linux Mint 7 Gloria onto my brothers laptop, which used to have an illegal copy of Windows XP Professional on it. He got fed up of the notification at the bottom and asked me to install Linux, which I did. Everything seems to work fine except certain websites don't work, like Facebook. I think that it might have something to do with Adobe Flash Player not being installed. Any help??