I think the overhead discussion, while true, is confusing the OP and moot anyway as the relative overhead on both the laptop and the desktop should be the same unless the MTU size has been tweaked significantly.

Sunny...to determine why one computer is faster than the other, you would have to do some testing by downloading the same file on both machines in exactly the same manner and at the same time of day and post numbers and hardware specifications. However, given your other posts regarding modem issues, proxy/IP changes, registry fixes, hard drive replacements, blue screen of death errors, and other hardware upgrade discussions, I'm wondering if your machines are all that healthy and working properly to begin with.