Many of us who play on servers outside their country face a lot of lag and latency issues.
Some of this is on the OS side and can be fixed..
Here is an automated program which fixes and patches several Windows Os registry and settings.
http://www.speedguide.net/files/TCPOptimizer.exe
Works for all the Windows OS from Win 7 to XP , even WIN 98 & 95.
This is the link for more general information for this utility as well.
SpeedGuide.net :: TCP Optimizer / Downloads
This worked for me and so I vouch for you all.