there is some kind of monitoring system on my comp. how do i detect it

hay ok thanks for opening this
well i got a computer from my uncle cause i did some work for him
but he said that he put some kinda monitoring system on my computer.i am the administrator i just dont know how to find it.he said that he would get a email if i did anything dodgy so maybe thats a clue?and he said he could go through all my website history and all my programs that i have been on. another hint?

please help i want to be able to surf the net with out having a big brother

thanks , cameron