I am currently upgrading machines from xp pro to windows 7 pro. On my xp machines, I have no issue transferring files over to a winidows 2003 server. But on my new windows 7 machines, I cannot transfer larger files to my windows 2003 server. HELP!?!?!?!?!?!

Which Anti Virus program are you using? Are you using SEP?If yes what is the version of that?Also if you have SEP remove NTP and then try.

I suggest you troubleshoot in Clean Boot Mode. How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7 http://support.microsoft.com/kb/929135 If it does not work, please try to disable auto tuning and see the result. You can refer: Network connectivity fails when you try to use Windows Vista behind a firewall device http://support.microsoft.com/kb/934430Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.