OKAY, THEN! TO CLARIFY.....
The computer you're on now, probably is an average windows computer (unless ur on linux or mac), and you're probably the admin. Say you're not. Is there any way of taking down the firewall? These 3 computers have no firewall apart from the default windows one as they are only in their own 3 comp network. THEY ARE NOT ON ANY SCHOOL SYSTEM. the rest of the school computers are. Is there any way of taking down the firewall (baring in mind that I can get to the command prompt and fully use it)
OK...
1. do these computers have internet access? If they do, then they are on the school's network.
2. on the schools network = schools firewall/web blocker/proxy.
let me give you an idea of how a typical school network is configured as I've BTDT.
Typicall each school campus is treated as a seperate network segment. Possibly and probably its own vlan if the admins are worth anything. Each campus will typically have a core router, a dns server, probably a small local file/print server, and more than likely a domain controller.
Now, each campus is then tied back in to a centralised location, like the admin buildling, where the email servers, file servers, custom apps are all kept.
From there the admin building is tied to the internet through a firewall, web blocker, proxy server ( these could be all one device or seperate appliances depending on the vendor). This ensures that all outbound and inbound internet traffic is controled at one single point.
The exception to this are the smaller school districts that might just have dsl server or T1 service and host all or most of their apps on campus, but thsi is rare.
So, evading a proxy or firewall is no longer common at schools. Every attempt to do so is probably logged as I do here at my office.