Sorry...another suggestion. You may also want to look in your system tray, where your "Clock" is. Make sure there are no programs like Limewire, Frostwire, Napster, or Kazaa running. If they are, right click on them, exit out of them, and try to connect again. If you've got a Peer2peer file sharing program running, it could be eating up your bandwidth.
In addition, while your down there, look for any programs that you're not familiar with, or that you don't remember installing. Such programs could be "false" antivirus or spyware programs that mascarade as protection, but eatup bandwidth by turning your computer into a bot server (a computer that has been taken control of by a virus, which uses your computer to increase the hackers bandwidth in his "botnet"). Unless your computer is acting really haywire tho, this probably isn't the case.
I'd run all spyware and antivirus scans tho, just to be sure. If this doesn't resolve the problem, open up your DOS window like you would in the suggestion above, and type in the following commands...
netsh int ip reset resetlog.txt
netsh winsock reset catalog
netsh int tcp set global autotuninglevel=disabled