by default, windows reserves 20% of your entire bandwidth
from your pc. this is for such cases as for many heavy microsoft apps to use. but ive have tested this and windows still works great. IE is about 10% faster
go to run
type in- gpedit.msc
click administrative templates
then click network
then click QoS Packet Scheduler
then limit reservable bandwidth
check enabled
and set limit % to 0.
then u get a full 100% of your bandwidth!
ps. this does not increase your internet speeds dramatically...just a little.but every bit helps!