NThell

best thing to do is a speed test go to

gamefiles.virginmedia.com/blueyondergames/demos/

download two large files i recomend

battlefield 2 demo gc.zip
d3demo.exe

watch your transfer rate, you should receive up to 2560 KBps

this is ur max download bandwidth.

check the results and see if you have any large amount of speed reduction
if your using a router connect the pc direct to ur modem

hope this helps