what are my student rights?

I am a college student and living in dorms on campus. I have to use the internet set up through the school. Does the school have a right to spy on what I do on the internet? I do nothing illegal and have never given cause for suspicion. To access the internet, I had to download a program the school says it just a virus scanner. Yet, my spyware detector/remover always sees it as spyware. I know some programs can look like spyware without actually being spyware; but, ever since I downloaded this virus scanner, I am blocked from looking up certain sites. I tried looking up other legal websites and a couple of state government sites about schools and what they can and can not do with regards to the internet, and I can not access them through the school. I took my computer to a friends house and used his internet setup and had no problems with the sites. It is only with sites I try to look up regarding my rights to privacy, and it is only when I use the internet through my school. Am I just over-reacting? Or, is there something going on they can't do and they don't want us to find out about it? Is it legal for my school to use a spyware program to watch what I do and block me from sites?