Do you check your ping in Online games ?
If your ping is fine it may not be the Internet sometimes other players with high ping could be the issue also
If your video card has wobbly drivers you will get Micro stutter that is lag performance because the drivers suck
Before you try to recure the Internet connection try newer drivers I keep hearing on here Nvidia has a new beta driver that fixes things like that so check out your options
Most of the time i wouldn't do a registry fix to speed up a connection rule out all potential issues first