There are lots of bandwidth test sites you can use on the Internet to test your throughput. The one I always use is:
http://bandwidthplace.com/speedtest/ <-- on this page, click the link for highspeed test
(I have RoadRunner cable, and I get between 2.5Mb and 3.1Mb download)
Don't forget to do Windows housekeeping stuff. You know, like getting rid of unneeded startup programs, cleaning out spyware, yada yada.
--Glanzer