A search here hasn't located what I'm after. If it turns out that similar questions have been asked and answered a gazillion times, my apologies (and I'd be much obliged for a link to one of the threads in question here).
A friend of mine, using CS4 and the almost-latest version of Camera RAW, finds quite a few camera-specific presets in ACR's Presets panel, including those for his camera. I recently updated CS2 to CS4 and have been unable to find any of these presets when I use ACR. Instead, I see only two presets, one of which I created myself a long time ago when I used a much earlier version of ACR, and one created just recently.
So I've been searching high and low on the drive where CS4 is installed, to locate files that might conceivably be ACR presets. So far I've found some buried deep within C:\Documents And Settings -- files with the extension .DCP and with October, 2008 modification dates. Whether or not those are supposed to be usable with Camera Raw 5.6, they aren't showing up in the Presets panel. Only the two referred to above appear in that panel (both of those, which I have located on the hard drive, have the extension .XMP, not .DCP).
If camera-specific presets usable with ACR weren't part of my CS4 upgrade after all, where might I download them, and what is the right location on the hard drive for them so that ACR will "see" them? (I'm interested mainly in Nikon D3/D3s/D700 presets.)
Thanks in advance...