^ limiting download speeds over http? How exactly do you suppose they do that? I have never heard of such a thing - limiting p2p sure, limiting download over http?? That is some pretty fancy tech to distinguish the difference, I would guess more something on your box doing the restriction like antivirus scanning would be my first guess.
I would boot a live CD of your fav linux distro and try that - are you still slow? Point to a specific download so that others can verify its not the server doing it.
Ok lets do a test, I thinking from where you saying your seeing slow downloads is web installers grabbing the file?? So here just did a test from your mentioned company nvidia
Let it grab atleast 100MB, unless your really really slow but give it some time so we can get a good picture of your overall speed
So here I took shot when 100MB had downloaded and I was seeing pretty much max for my connection 1.9MBps
Lets see what you get - here is link to site
here is specific link