1. make sure your logged on as actually "Administrator". do not log on with any account that just has administrator privileges.
2. start - run - type gpedit.msc (not available in home version)
3. expand the "local computer policy" branch
4. expand the "administrative templates" branch
5. expand the "network branch"
6. Highlight the "QoS Packet Scheduler" in left window
7. in right window double click the "limit reservable bandwidth" setting
8. on setting tab check the "enabled" item
9.where it says "Bandwidth limit %" change it to read 0
Effect is immediate on some systems, some need to re-boot. This is more of a "counter what XP does" thing. In other words, XP seems to want to reserve 20% of the bandwidth for its self, even with QoS 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.
OR you could just uninstall it ;)
This tweak is for broad band cable connections on stand alone machines with winXP professional version - might work on Home version also. It will probably work with networked machines as well but I haven't tried it in that configuration. This is for windows XP only, it does not work on win2000. I use 3 Com cards so I don't know how it works on others at this point. It does not involve editing the registry. This tweak assumes that you have let winXP create a connection on install for your cable modem/NIC combination and that your connection has tcp/ip - QoS - file and print sharing - and client for microsoft networks , only, installed. It also assumes that winxp will detect your NIC and has in-box drivers for it. If it doesn't do not try this. In the "My Network Places" properties (right click on the desktop icon and choose properties), highlight the connection then at the menu bar choose "Advanced" then "Advanced Settings". Uncheck the two boxes in the lower half for the bindings for File and Printer sharing and Client for MS networks. Click OK
1. From the windows XP cd in the support directory from the support cab, extract the file netcap.exe and place it in a directory on your hard drive or even in the root of your C:\ drive.