Secara default Windows (Win XP Pro dan 2000) sebenarnya juga mengurangi bandtwith kita sebesar 20%, 20% ini digunakan window untuk mendownload update untuk window. Berikut langkah untuk menghilangkan pengurangan bandwidth tersebut :
Klik Start->Run->ketik"gpedit.msc" (tanpa tanda ") Ini akan memunculkan tampilan "Windows Policy". Kemudian masuk ke : Local Computer Policy–>Computer Configuration–>Administrative Templates–>Network–>QOS Packet Scheduler kemudian di tampilan kanan pilih "Limit Reservable Bandwidth", disitu tertulis "Not Configured" -> doubel klik (ada tampilan baru, "Limit reservable bandwidth Properties").
Jika ingin tahu keterangannya buka di bagian "Explain". Di situ tertulis keterangan windows secara default menggunakan 20% bandwidth kita. Kembali ke "Setting" dan pilih "Enabled" lalu ganti 20 % menjadi 0%.
Let me try it..
By default Windows (Win XP Pro and 2000) actually reduce your bandwidth by 20%, this 20% will be use by Windows to download its update. Below are steps to lessen that allocated bandwith:
Click Start->Run->Click"gpedit.msc" (without ") . Windows Policy will pop-up, Navigate to "Local Computer Policy"->Computer Configuration->Administrative Templates->Network->QOS Packet Scheduler ..Right window choose "Limit Reservable Bandwidth", there it should set at "Not Configured" -> double click (New window will pop-up, "Limit reservable bandwith Properties").
If you need information about this open up the "Explain" part. It explain by default windows uses 20% of our bandwidth. Return to "Setting" and choose "Enabled" and change 20% to 0%...

I am just translating it I did not try it