If you have Windows XP, try this. Everyone that has tried it says it works, tell us if it works too. You should be logged as Administrator (not even accounts with administrator privileges).
1. Start – Run – type gpedit.msc.
2. Expand the Local Computer Policy / Administrative Templates / Network Branch.
3. Highlight the QoS Packet Scheduler in left panel.
4. In right panel double click the Limit reservable bandwidth setting.
5. On setting tab check the Enabled item.
6. Where it says Bandwidth limit % change it to read 0.
The problem is, XP seems to want to reserve 20% of the bandwidth for itself. Even with QoS disabled, even when this item is disabled. So why not use it to your advantage.
To demonstrate the problem with this on stand alone machines start up a big download from a server with an FTP client. Try to find a server that doesn’t max out your bandwidth. In this case you want a slow to medium speed server to demonstrate this. Let it run for a couple of minutes to get stable. The start up another download from the same server with another instance of your FTP client. You will notice that the available bandwidth is now being fought over and one of the clients download will be very slow or both will slow down when they should both be using the available bandwidth. Using this “tweak” both clients will have a fair share of the bandwidth and will not fight over the bandwidth. Try it and tell us if this works.