Reply to SD
Saab, I suspect the you have already answered your own question - Re the TCP/IP Stack question. I'm not sure if the problem is symetrical ? Have you had the chance to try W7 to W7 or XP to XP transfers: as well as W7 to XP and vi ser versa.
I do not know about your Network Topology. Are the MTU Values optmised ?
Is there an anti Virus checking the packets on either or both PC's.
Have microsoft made changes in W7, re the packet handeling - Re member the brooha over "Raw sockets" as to whether the packet addres data and the packet contents were handeled, is there a bottleneck in the packet protocols.
On a more benign level - I had "Great fun" with a Belkin PC Network Card - In the advanced Network settings in XP - There was a power mizer function and it took several seconds for the card to reach its full data through put.
Just a few snippits fron the totally uninitiated.
CAT III
PS Saab there's an article on the web site of a "Well Known Mag" re the long term performance of W7 64 Bit - Think of a Spherical lump of the Stuff that Bees make.- I have not read it yet but wil do - It might provide some ideas
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