ACR does not support the D700 raw files at the moment; the next version will do that. In the meantime there is a temporary remedy: making the D700 raw files appear as D3 (the sensors appear to be identical).

A tiny DOS command line program can be downloaded:

Program download

It does nothing beside changing the model name string from D700 to D3. It has two parameters: the input file name (a D700 NEF) and the output file name; if the second parameter is not specified, then the output file name will be "input name_D3 input extention".

Several people have already been using it with ACR. Someone pls try it with NX (both the older and newer), please report the result here.

THERE IS NO GUARANTEE, THAT THE RESULT WILL BE PERFECT.

There could be some tiny difference in the sensors, which requires a somewhat different color conversion, etc.

KEEP THE ORIGINAL NEF for the time, that the newer ACR version accepts it.

There is no expressed, nor implied guarantee for anything but that the program is not malicious.

There's a much easier way: Adobe's DNG converter.

I don't believe the newest Adobe DNG converter supports D700 files yet - that will come with a new version of ACR - but then we won't need to convert to DNG first!

Any way at the moment to convert these files on a Mac without having to use windows? (I meant so that we can read RAW files in ACR - I tried the NX2 that came with the camera and that works fine of course but I can't believe how slow it is)