If you have the SD card reader/writer, you don't need the PC program to update your unit. Just when you click on to download the software update, click on browse to choose where you want the software patch saved. In my case, my SD writer/reader drive is drive F, yours may be a different letter. Save to the correct drive/folder and the rest is a snap. After it has downloaded to the SD card, just put the card in one of the SD slots on the unit and power it on. It will ask you if you want to install the 4.510 software. You choose yes and it does all the rest.