I am running into the exact same problem with my network.
I have 3 computers, all running XP SP1, Linksys router and a cable modem. My personal computer seems to be the troublemaker, the connection works fine until you try and copy more than about 200 megs to or from it. It hangs and eventually gives you the network reasource unavailable message. After that, the only way to get the connection back is to restart it. I have tried the following:
New Cabeling throuought the house,
New Router,
New NIC,
Remove/Reinstall all Windows networking services.
Virus scan
Nothing seems to make a difference. Shortly before this problem appeared I was moving some hard drives between computers, however I tried pulling out all the new ones I put in and I still get the problem. Let me know if you fund any info on this.
