3 into Router on ADSL can you control inconsidrate or selfish loads?!?

We have 3 PC's into a D-Link DSL-504G router on a 512/128 plan. Sadly some people can be inconsiderate and download songs,etc while others are on the net and effectively hog the bandwidth and make myself not even be able to load web pages at any sort of effective (bearable) rate. I'm the admin of the router and "PAY" for the ISP account so is there an app that I can use to manage individuals bandwidths, preferably for free and effective with lesser complexity.

Any suggz plz I had to get off the net earlier as I just couldn't use it

 

You can always pull the CAT5 plug, or change the password.

Tat way you get to see your kids, or room mates, or whoever is on the other end.

Besides, you don't want he RIA on your case (the excuse).