I need to create a windows login UI for Windows 7 & Vista which logs user name and image from webcam (replacing their login screen). I don't know where to start from. Can I do this in C# or will I have to use C++? Any link will be helpful.
If you just need Windows 7 and Windows Vista support, you are looking for Credential Provider. You can find some samples in Windows SDK.
If you want to extend pre-Vista Windows, you are looking for GINA
来源：https://stackoverflow.com/questions/4516578/how-can-i-customize-the-login-screen-for-windows-vista-7