Hello: Please help with this vexing problem. I have 3 identical PC's (Dell E521), connected to the same LAN network. All 3 PC have ESET SS 4 installed. Network file transfer starts and stops repeatedly. Usually smaller files, <100MB can transfer without problems. Anything larger, the transfer will start, then come to a stop, after a few minutes will start again, only stop then start again. It usually takes 4-5 stops and starts to finish transferring a 300MB file. On very large files, >1.5GB, it can stall permenantly. I have tried switching cables, NIC cards, router: no luck. I have verified the NIC cards have the latest drivers, and the router has the newest firmware. Finally, I disabled the ESET SS firewall on both the sending and receiving PC: the problem disappeared. I have found that both side must be disabled. I would appreciate any suggestions about this problem. Thank you very much.