The Only Digital Cameras that can function as a webcam are the ones made in China. And there is no support for those cameras.

Since you question is specific to Windows 7, I suggest you post your question on the Windows 7 Forum.

Here is a link:

http://forums.cnet.com/windows-7-forum/?tag=f06-fd;StickyWin_1263483057859

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You can also look to Logitech for an answer.
They build and support webcams.

Here is a link:

http://www.logitech.com/index.cfm/webcam_communications/webcams/&cl=us,en

If you don't find what you want to know, click on their "Support" button.

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