I'm sorry Phils, but I have to agree with GRJ, this does not resemble any issue I have seen a 321 produce with an o/s. I regularly move about 1.1-1.2 TBs of data to and from my 321 and have never had it lock the o/s. As a start point, I would suggest that you go through you PC thoroughly and see what underlying conditions it might be having that could cause this to happen and then repair that first. You could start with a very thorough defrag of your drive. You may have a badly fragged drive and you may also be low on swap file space, it might be set to low. You could also have a corrupt file that your o/s can't deal with when it comes to moving it, so it crashes. Another place to look would be for a faulty memory module that may be giving XP problems when it goes to cache the files. And, it could be your 10/100 NIC card, it may be throwing to may collisions for XP to think the transfers are going reliably All of those things could be causing XP to crash. Also, one other thing, do you actually have enough free space on the 321 to store the data you intend to move? You said you had several thousand songs, but what does that translate to in megs/gigs, are your drives in the 321 big enough or have enough free space to handle that amount of data being moved to them?
Once you have checked out the basics, then report back and let us know your findings. Possibly then someone here can give you more steps to try. But really and truthfully, I cannot recollect any time that I have ever seen a 321 cause XP or any other flavor of Windows to crash.
Good luck with your hunting.
Sincerely yours,
Ryder