On the Mac, the Download is saved to your Downloads folder or wherever you have asked your Internet browser to save them. I believe you can do the same on Windows, but that’s something you will have to figure out yourself since I haven’t used Windows since switching to Mac in 2004.Once you have downloaded this file you have to GO BACK to the page you chose the GH4 from. Scroll about half way down this same page to begin seeing directions for both Windows and Mac.
The new information below is based on support from Robert Kozlarek of Panasonic US. Make sure the camera’s battery is completely charged. Download the latest firmware update for your model by clicking on the “Download Ver. X ” link to a location on your computer (we recommend the “Desktop”). If your computer has a media reader, please insert your formatted SD Card from your camera. Open the zipped firmware file that you downloaded to the desktop. For “PC” users, locate your SD Card by clicking on, or opening the “My Computer” or “Computer” on your desktop or your “Start” menu. If you choose to leave the SD Card in your camera, connect the camera to the PC with the USB cable. Depending on your PC, and the age of its operating system, you may not be able to directly write to such large cards. I’m hoping by bringing this to our readers, and by getting more input we can hopefully convince them they desperately need to update the ease of use on their firmware website. Secondly, you need to get to the Main Support Page to start all camera and lens firmware updates.If you want horror stories about Olympus camera firmware updates which are caused by a direct download from a web page directly to camera, take a look at this thread on DPReview.The SD card is the way to go even though this whole process is painful.Turn the Camera off, insert the SD Card if you copied the firmware to the card while inserted into the computer. Turn the Camera power on and press the “Playback” button. When the Camera has completed the firmware update it will turn itself off and then back on. This page is confusing since it shows not only the newest GH4 update but it also shows a list of all prior updates.The Camera’s LCD screen should now be showing a screen asking if you desire to “Update” the firmware. Even though the update you are after is described at the top of this page, you actually have to scroll all the way down to the bottom of this same page to see the Download option you’re after.
If Nikon Transfer or View NX 2 is installed, Nikon Transfer or Nikon Transfer 2 may start automatically; exit the application before proceeding.