Freelancer was made to run on systems like Windows 98. Ever since the Vista operating system was created there have been more problems with Freelancer and every other game that came out between 2000 and 2006. Microsoft never had a fix for Freelancer, which is why you may have problems setting up in multiplayer or even setting up on a server (I tried it, and it was a royal pain in Vista :x ).
It seems that Freelancer flourishes in either Windows 2000, XP and XP Pro, and Windows 7. Unless changing your operating system will create a problem for you, I would recommend the aforemention operating systems. I've been with the Reactor close to six years, and all the posts I've came across say that they prefer any OS over Vista. You can look through the technical posts in the Reactor or you may want to go to a favorite resource of mine, the EOA Players Consortium (<!-- w --><a class="postlink" href="http://www.eoa.seriouszone.com">http://www.eoa.seriouszone.com</a><!-- w -->). Hope you can find an answer at either of them.