tested this last month*from my friend in school
he said this will increase your download speed but you will unable to browsing (while you dling) // it does not have any effect for me thought ..
ps. only win7 enterprise & ultimate have the gpedit
to those dont have gpedit you can get it here
im using home premium, which mean doesnt have gpedit and that helped to enable it =)
Sorry for outside link.
^msconfig is a different thing