I have a laptop, which has a 500GB hard disk and with MBR partition, and I install my windows8.1 on it, but I left ~75G unused which I would like to use it for OpenSuse13.1. Now I have 2 USB, one is Gnome Live 13.1, another is standard DVD install ISO.I tried to insert Gnome live 13.1 and no problems, it recognized my unused 75G partition, and recommend my Linux partition as below:/dev/sda6 --> swap/dev/sda7 --> //dev/sda8 --> /homeI cancelled this installation and try with DVD iso, and now I get an error when I try to use my 75G unused partition as below:Your system states that it requires an EFI boot setup, since the selected disk does not contain a GPT disk label YaST will create a GPT label on this disk. You need to mark all partitions on this disk for removal.I would like to keep my windows and create a dual boot system, but I am stuck here. anyone please give me some suggestions? 
How to install after windows 8.1 with MBR partition
opensuse;dual boot;gpt;mbr
It sounds like you're either booting Windows 8.1 in legacy/BIOS/MBR mode (as opposed to EFI/GPT mode), or YaST is buggy and thinks that you have EFI booting enabled even though you don't. Another possibility is that your laptop's BIOS boots optical drives in EFI mode by default, causing YaST to load in EFI/GPT-only mode. Therefore, if there's a BIOS option in your laptop to turn off EFI booting, I suggest you set it. Another thing to try, is when you bring up the laptop's boot menu to select boot from DVD-ROM, if there are 2 options Boot from DVD - EFI and Boot from DVD - BIOS/legacy, pick BIOS/legacy.If you're really stuck, why don't you Google your laptop's exact model number with terms like boot optical drive in BIOS/legacy mode - this should hopefully point you in the right direction.