If you want to Increase your internet bandwidth by more than 20% in XP follow this procedure
1.make sure your logged on as actually “Administrator”.
2. start – run – type gpedit.msc
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
10. go to your Network connections (start->connect to->show all connections).
right click on your connection then under the General or the Networking tab
(where it lists your protocols) make sure QoS packet scheduler is enabled.
11. reboot if you want to but not necessary on some systems your all done.