Download speeds slower than other computers on network

Hi.

For a little while now I've been having some problems with web pages not loading as quick/downloads taking longer than they used to and I just put it down to people downloading or otherwise hogging the bandwidth.

I've since asked other people in the house and they've said their connections/speeds are as fine as they ever were.

I've run several speed tests and I've found I'm getting appalling download speeds as shown here: http://www.speedtest.net/result/1767192706.png
Straight after running that test I hopped on to my girlfriend's laptop and ran the same test and she was getting ~2.6Mbps.
I then went back and ran it again on mine but it was as slow as before.

Does anyone know of any possible reasons for this sudden drop in speed?
It's making it difficult to do pretty much anything.


Thanks in advance.