Now
START - RUN
On Run dialog box enter "gpedit.msc"
A new window(Group Policy) will open up,on it
select Administrative Templates > Network > Qos Packet Scheduler
On the Right - SETTINGS there is "limit reserve Brandwidth"
Double click - Enable it and change Brandwidth limit [%] to 0
Now this has been done, so you can use the 100% of you brandwith.As default Windows
limits 20% of its brandwidth for windows services.