If your subscription for software updates is not expired, you can download the software to a new SD card (preferably 8GB) from autel website using an SD card reader connected to your PC with the PC Suit installed (use DS708 update software of the PC Suit). If your subscription is expired and you do not have a backup of your software, you are out of luck, you need to renew your subscription before you can download the software. Good Luck

 very detailed explanation, thanks!