Developers starting to make their created Windows 7 apps work for Windows 8 as well, example is Win 8 login Screen Capture which developed on idea on windows 7 login screen camera by the same developer which lets you capture and save Windows login screen as a PNG image.
Using Win 8 login screen Capture
Download and extract the program archive contents to a folder and run program executable, from the screen click “install program”, the program automatically backs up utilman.exe file in ”%Windows\System 32” folder and replaces it with the program file. So the program takes necessary measures, you don’t need to worry.
Now use Win + L buttons to lock your PC and double-click on lockscreen click “Ease of access” button on lower side of left corner of the screen and click on Snap Login Screen button to capture your login screen and save it via Explorer with desired name in PNG format.
To uninstall the program, run the program executable again and click “uninstall program” button on the window.
Win 8 Login Screen Capture works on Windows 7/8 and requires .Net framework 4 to be installed in Windows 7 to work.