How to Jailbreak 4.3.2 iPhone 4 using RedSn0w (Windows)

Step One
Create a folder named Pwnage on your desktop and download the latest 4.3.2 IPSW and RedSn0w 0.9.6rc14 then place them in the Pwanage folder.

Extract the RedSn0w zip file in the Pwnage folder.

Step Two
Connect your iPhone and launch iTunes then select your iPhone from the list of devices.

Next hold down the shift key and press the Restore button.

Navigate to the Pwnage folder you created earlier and select the 4.3.2 firmware ipsw and continue.

Step Three
Once the update has finished open the Pwnage folder and launch the RedSn0w application you extracted earlier.

Once RedSn0w has opened click the browse button and select the 4.3.2 firmware ipsw from the Pwnage folder and click open.

Step Four
After the firmware has been verified click next to continue.

RedSn0w will now prepare the jailbreak data.

Step Five
Now you should be able to select the jailbreak options you would like.

Make sure you select Cydia and click next.

Step Six
Make sure your iPhone is plugged into the computer and it is switched off then click next.

Step Seven
RedSn0w will now guide you through the process to enter DFU mode just follow the onscreen instructions.

Step Eight
If you followed the instructions correctly your iPhone should reboot.

RedSn0w should now begin uploading the new RAM disk and Kernel to your iPhone.

Step Nine
Once complete you will be notified RedSn0w is done click the finish button.

Step Ten 
Your iPhone will reboot once it has finished you should see the cydia icon on your springboard.

That's it your iPhone is now jailbroken on 4.3.2 firmware enjoy :)