Make sure you are logged on as actually "Administrator". do not log on with any
Account that just has administrator privileges.
Start - run - type gpedit.msc
Expand the "local computer policy" branch
Expand the "administrative templates" branch
Expand the "network branch"
Highlight the "QoS Packet Scheduler" in left window
In right window double click the "limit reservable bandwidth" setting
On setting tab check the "enabled" item
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, programs can request up to 20% of
the bandwidth be reserved for them, even with QoS disabled, this is no big deal and
most programs do not request it. So, although QOS has caused a big stink because
people think it reserves 20% of their bandwidth, you can still disable it, just to be
sure.