This now lets you use the KFU util and others to root & install new OS etc
You need to have installed ANDROID SDK and extras-usb & JAVA se
you will need to modify the following two files:
a. adb_usb.ini – You can find it under your Users\YourUsername\.android folder
In a typical Windows 7 installation, adb_usb.ini will be located under C:\Users\YourUserNameHere\.android
Open the adb_usb.ini file with a text editor (Notepad is just fine) and add the following line at the end (on a new line). Save and exit.
android_winusb.inf – You can find it under the folder you installed the Android SDK, in my case C:\Program Files (x86)\Android\android-sdk\extras\google\usb_driver
Open the file with a text editor (notepad is again good enough), locate [Google.NTx86] section and also the [Google.NTamd64] section and add the following lines to each section, like in the screenshot.
%SingleAdbInterface% = USB_Install, USB\VID_1949&PID_0006
%CompositeAdbInterface% = USB_Install, USB\VID_1949&PID_0006&MI_01
Note: If your device list is empty, maybe you plugged-in Kindle Fire before you installed Android SDK and Android USB Drivers. In this case you’ll need to force load the Android USB driver. Right click on My Computer and select Properties then navigate to Device Manager. Under Other Devices you should see Kindle with a yellow icon containing an exclamation point.
Right Click on Kindle name and select Update Driver Software. A Dialog will pop-up asking how do you want to search for driver software. Select Browse and point toward the folder containing Google USB Driver (in my case C:\Program Files (x86)\Android\android-sdk\extras\google\usb_driver). Select Next and proceed with the installation, choose Install this driver anyway when prompted.
Ok now you can
cd C:\Program Files (x86)\Android\android-sdk\platform-tools
d. type adb kill-server followed by enter
e. type adb devices. If everything is fine, you should see a connected device (your Kindle Fire)
You are good to go
Cheers to dudes @ "reviewhorizon.com/2011/11/how-to-root-jailbreak-kindle-fire-using-one-click-solution-superoneclick-also-enable-sideloading-apps/"