This tutorial was done on Windows 7, as long as you've followed the driver installation guide for windows 8 then the rest will be the same.
Begin by having a RPi flashed with the Raspbian Operating System and then push the debug clip onto your Pi. After then plug in the debug clip to your computer or laptop.
Windows will now detect the device and install the drivers on Windows 7 or if you are using windows 8 it will then use the drivers you have installed.
Next navigate to Start -> Devices & Printers / Search -> Devices and then you should get a screen like the following appear.
Next click on MCP2221 to view details of the clip's IC
You should now have the following window open:
At the top click the tab that says "Hardware", after which the following screen should appear
At the bottom of the list you should see the device for a USB Serial Port. Make a note of the com port which is different for every machine, mine has set it to com4. The com port may also change depending on what USB port you plug the clip into and if you use multiple clips at the same time.
On the putty download page scroll down to download just Putty.exe , after it downloads you may move it to the desktop or documents folder and then launch it. A screen like the following should appear.
On this screen we need to change a couple of options.
Your screen should now look like this.
Finally click Open and the connection to the Raspberry Pi will open.
Press enter once and the login screen should appear for the terminal.
Congratulations! You have successfully setup the RPi debug clip on windows.