Im apart of a school network and outt of all the computer connected I have the slowest connection..Helpppp!!?

Ok Im a part of our school network of say about....400 students, at first I thought it was my network until I had a friend bring his computer to my room and his computer moved as if speedy gonzalez directed the inside of his computer so I tried to download a file on to his computer and it was there in 6 second..when my computer would take up to 6 days for the same download. I have tried the auto-tuning, configuring the regestry keys, disabled windows update 20% reserved bandwidth, and some more please help me I have beenn at this for a week now...