Installing dfu-util files

Sorry, I did indeed type the wrong command in the first place.

When I typed in the correct command, I got:

I am operating on Windows 7, and I followed these instructions:

In step 3, when I tried to open the build-mingw32--libusb file, it did not open on cmd. So I used "open with..." to directly open the file with the command prompt but that ended up with this:

...and I am not sure what to do.

Also, thank you for the quick response.