Hello and welcome to the forum.
My first thoughts would be either any Security Suite that you might have installed or some third party application like Bonjour which includes something called mDNSresponder.exe. But that wouldn't explain why the computer works fine in another location.
You could try to disable IPv6 by unchecking it within the properties of your network adapter, sometimes that seems to get in the way with some routers.
The only other thing that comes to mind immediately would be that the router you are using at school might need a firmware update. The fact that others don't seem to be having the same issue is not really indicative of anything unless they are running the exact same hardware and software that you are.
Regards
Randy