Disabling your anti-virus may help but it can put your computer at risk. Since most anti-virus\' use alot of computer resources I have found that winpatrol is the best thing to have running in the background so I can have my anti-virus off while I play games.
Err, do you ever heard of those patches launched by Microsoft that prevents those kind of viruses/trojans to infect your computer? Well, I kinda suggest you start downloading them ... Then you won\'t have to run antivirus programs on your pc, significantly slowing down your PC and your internet connection.
And as for the NT thingy, well mostly is in your head ^_^ ... psychological problem, or name it how you want. Switching the compatibility in Windows makes that application (in theory, because it doesn\'t work everytime) compatible with other os. Of course, NT is a server OS, that optimizes the internet connection for better use, but that doesn\'t change anything in xp ...
Though, I strongly recommand you Windows Server 2003, good for the lan, good for the net.
Anyway, in conclusion, the main problem is your own system. The net could work better sometimes, sometimes it doesn\'t, that\'s why you believe you don\'t have lag anymore ^_^
