Improve BSNL 3G Download Speeds On Windows & uBuntu

I've seen steep decrease in download speeds I experience using BSNL 3D Data Card. I even wrote a review of the speeds on VoiCE: #-Link-Snipped-# and #-Link-Snipped-#

I'm unable to tell whether the choice of operating system has any effect on the download speed. Logically, OS shouldn't affect the speed, but I have experienced better download speeds on uBuntu than on Windows 7.

If anyone's got tips for increasing BSNL 3G Download speeds, please share them in this thread.