Long story short, The KISS FCs do not come with firmware flashed on them. Before you can connect with the KISS GUI, you will need to download and install DfuSeDemo from an indirect link on the FlyDuino site. You will also need to download the latest (1.2) firmware from FlyDuino. After plugging in the FC into your system with the BOOT button pressed, it will go through driver installation. It will most likely install the wrong one. It will probably show up in device manager as STM32 BOOTLOADER. Select that device, click [Update Driver], [Browse my computer for driver software], [Let me pick from a list of device drivers on my computer], [Next], [Have Disk], and browse to C:\Program Files (x86)\STMicroelectronics\Software\DfuSe v3.0.5\Bin\Driver\Win7\x64\STtube.inf (if you are using 32 bit windows you will need to adjust path accordingly)
After this driver installs, the device should show up as "STM Device in DFU Mode" once you get this far, the correct driver is loaded and you can flash the firmware.
If you get to the point where you have "STM Device in DFU Mode" when plugging in with the boot button, then you should be able to follow the rest of the firmware flashing steps using the DfuSeDemo. I can step through some more steps if you get this far.
Cheers!
LitterBug