need help and advice

ok here is what i want i want to know is there a way of stopping somone installing certain programs ie chat ones i bloody hate them and i have a feeling a mate will be popping around mine to install them ive already set up "some" restrictions through norton lol but i want to stop him installing just chat ones lol

anotherthing i need is a download monitor so i know when im getting close to my download cap of 30gig a month if anyone knows where i can get one it be appreciated

thanks in advance for the advice if you can help!

Which OS are you running? ...including the SP installed if any.

at the moment windows xp with no sp till friday when i get my net installed!