Improve file download performance in Windows 2003

I have a Watchguard x1250e firewall and a fast network setup at pryme.net in Ashburn, VA. I have Verizon FIOS here at the office (50 mbit) and did a test download from a URL they provided me and I get 5.8 MB/sec from their test file (probably off of Linux). But from my servers running Windows 2003 behind the firewall (x1250e) just using normal packet filter for HTTP, not proxy, very very basic config, I am only getting 2 MB/sec from my rack.

What do I need to do to serve downloads FAST? If I have a network with no bottlenecks, 50 mbit service to my computer, GigE connectivity in the rack, where is this slowdown? We tried bypassing the firewall and the problem remains so it's something in Windows 2003 I presume. Anything I can tweak to push downloads at 6 MB/sec instead of 2 MB/sec?

Any tips or tricks? Things to configure to get better HTTP downlo开发者_运维问答ad performance?

Pryme.net test URL:

http://209.9.238.122/test.tgz

My download URL:

http://download.logbookpro.com/lbpro.exe

Thank you.

It could be the Windows server itself. You could test for bottlenecks in memory, disk access, network access, etc. using PerfMon (1, 2) or MSSPA.