Capture Window as Image without Windows UI running

I've come to realise from a previous question that I can not screen shot a window when there are no active users logged in.

However, I am wondering if its possible to "convert" a window into an image somehow from memory without having the Windows UI running?

Thanks all for any help.

Update

Just to clarify, I think what needs to happen is to somehow fire off a redraw for a window and paint this to a file someh开发者_如何学编程ow rather than the screen. I am unsure how to event start with this though, any ideas?

You .... want to screenshot the login window? Use virtualization to make that easy

If you want to do windows-login screens yourself, implement/replace MS GINA

If I'm not wrong, I remember using UltraVNC running as a service was able to see the login screen just fine (on XP IIRC). After loggin in, you'd have to reconnect to get a connection with the actual session 0 (console session) of the desktop. YMMV but I'd look into that.

There is pre-existing software that leverages the VNC protocol to make (remote or local) screen snapshots or screen casts.

I managed to get this working with PrintWindow and firing off a WM_PRINT message. A little crude but it seems to work for now.