As near as I can tell, the only thing the driver might do for you is change the Icon in Networks. Interestingly enough, if I ask Win7 for a network map in the
Network and Sharing Center, it displays customized icons for the DNS-321 and DNS-323, and I never installed anything to make that happen. It's curious that it doesn't use them in Networks, maybe that's what the driver does.

It displays the generic "computer" icon in Networks on my Win7 systems. I don't routinely map a drive letter for the NAS, so it doesn't appear in
My Computer, but I have mapped a drive letter to it in the past. I used the standard Windows drive mapping feature to do so, again no drivers required. I also access the DNS-323 from the Windows XP Mode virtual machine under Win7, and that works just fine as well. I have mapped a couple of drive letters in the VM, no drivers required for XP either.
I personally am against loading unnecessary drivers, they can only cause you grief for the most part. This unit should work just fine with nothing but Windows.