I'll try sending a large jpg to myself and see just how big a file it will accept. I know there's a limit, but I can't find it stated.
To make W7 simply review NEF, I had to download (From Nikon) S-NEFCDC-190WF-ALLIN.exe It requires a reboot, and from then on it treats NEF like any other picture.
W7 offered to find the link for me as I tried to access the file - which was thumbnailed as a blank sheet.