My Nikon readers who use Windows are a bit used to this question by now, but it's probably a good thing to point out something here on sansmirror given today's news (we'll get to that in a minute).
Why would a computer OS need to support cameras? Well, correct thumbnails for raw files would be one simple example. When you're browsing through the OS looking at files, if your camera isn't supported you get generic icons for those files instead of a small thumbnail of the image contained in the file. Knowing what to do if you double-click on a file is another aspect where the OS should know something about where that file came from.
- On Macintosh OS-X, camera support comes through updates to Apple Digital Camera RAW Compatibility (ADCRC). ADCRC also provides the raw conversion support for Aperture and iPhoto. The current version for this is 4.02, and this file is automatically installed by the Apple software update system if you've got it enabled and are accepting system updates.
- On Windows, camera support comes from either the Microsoft Camera Codec Pack, or via a manufacturer's own Codec (Nikon has one, for example). The current version of Microsoft's Codec Pack is 16.4.1734.1104 (no, I'm not making that up). Windows 8 uses automatic downloads, like Apple, but Windows 7 and Vista owners have to manually download them.
Which brings us to today's news: Microsoft has updated the Camera Codec Pack to include support for the Canon EOS M, Nikon J2, Olympus OM-D E-M5, E-PL2, E-PL3, E-PM1, Panasonic G3, GF2, GF3, GH2, and Sony NEX-3C, and NEX-7. The update is available from Microsoft's Web site for Windows Vista and Windows 7 users.
Which brings up another point: note that camera support in the OS versions tends to lag camera introductions by a fair amount, and some cameras—Fujifilm's unique sensor models like the X-Pro1 and X-E1 are examples—don't tend to get supported at all.
Update: Apple added Nikon V2 support to version 4.03 released 12/13.