TCP autotuning

I understand Vista "tweaks" it's own connection, but why does it do it so
badly? If I run test downloads allowing Vista to self tune it rarely gets
even close to a tenth of my connection, despite using a download manager to
maximize speeds.

I found out how to turn off auto tuning, and also changed a file to allow
more connections, things are much better now, but I still need to adjust my
RWIN as this is tiny. Auto tuning goes the opposite and makes it so huge I
get packet loss left right and center. I adjusted this to perfection on my
old XP set up, but for the life of me cannot find out how to do it on Vista,
I just keep hitting a brick wall.

Please someone, if you are aware of how to tweak these settings please let
me know.

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