Downloading Custom Tone Curves

I was going to download some custom tone curves that I've found on

what appear to be reputable sites.

The folks all say it is a simple procedure ... and even provide

custom curves that one can download and save for installing.

But no one seems to mention if the downloads are compataible with PC

or Macs.

Doesn't it matter?????????

Also .. if after downloading a custom curve ... if I am not satisfied

and want to go back to the original Nikon curve ... where would I

find it?

pc or mac doesn't matter - its a nikon curve.

The original Nikon curves are always there - right in the camera menu.