Some C++ help

I'm working on rewriting/updating the code for a command line app that allows the user to change the screen resolution of the computer they are working from. I plan on adding a GUI interface to it, unfortunately, the original code, from the Res application by Meme Code, released under the LGPL, uses EnumInputDevices() and the built in function in Visual Studio 6.0 is missing some necessary symbols, so i recieve an error message each time. Does anybody know where I can find the updated and working .lib file that contains this function?

The readme in the source mentions the Platform SDK addon from Microsoft, however, I can't seem to find the correct version of the SDK.