"The problem seems to be with QoS packet scheduling, You don't need to disable it you need to decrease the amount of bandwidth it reserves for QoS apps to 0. To do this do the following:
Go to Start -> Run..., then type 'gpedit.msc'. Now, open the branches Computer Configuration -> Administrative Templates -> Network -> QoS Packet Scheduler.
Now, double-click the option in the right-hand window that says 'Limit reservable bandwidth', and then set it to Enabled, and the Bandwidth Limit to 0%
This fixed the problem for me, hope it works for everyone else!"
Try that solution also...it's from
Planet Half-Life Forums