>I really need it to download a new OS for my laptop
Most Linux distributions offer HTTP or FTP as an alternative to BitTorrent. Although the servers tend to have a lot of traffic, chances are you can find a mirror close enough to you to make the downloading go speedier.

I need the Alpha version of it and its only available with bittorrent.

Ive shut down my software firewall and it makes no difference.

My router has UpNp and i am behind it using NAT, with IP adresses assigned by DHCP. I think i maybe need to opena port on the router?

You need to make sure that your router isn't blocking WAN requests, and that any requests on ports 6881-6999 are forwarded to your computer's IP address (assigned by your router). Other than that I don't know.

hmm i enabled port forwarding to that range. It works now but is very slow. I think my router is doing something to make sure i dont take up all the bandwidth ;(

I know some ISPs will block or bog down torrent connections.

mine probably does then. i know it blocks incoming ftp, ssh and http so maybe you are right.

Your router is causing the issue.
BitTorrent opens ports on your machine and listens for connections from peers/seeders.

You're looking to use, not the offical BitTorrent client, but something like BitLord or BitComet. (stay away from Azureus).

So if your trying to torrent, you're going to experience slow speeds and intermittent performance, as the router is blocking 90% of the ports the Torrent client is wanting to open/use.

Temp Fix.. Don't use router for Torrenting.

no, i tried direct connection to the modem. I think its my ISP.

ill just have to do it round my friends house

If all ports needed are open and forwarding and the problem is still present, I say the ISP is blocking or bogging it.