How can I take a picture with my webcam in Windows 7?

Answer I wrote from another similar question. Technically it isn't built in, but it is by Microsoft - so hope that doesn't count as third party in your books. I find the best and quickest program to be Microsoft AMcap. It works via native DirectX functions and is very lightweight. It is a free utility available through the DirectX SDK - and here is a direct link to Amcap.exe.