Booting issues after installing

So I’ve been a Linux user for about two months, which makes me basically a beginner to all this stuff, so I feel like my issue is probably really silly but, hey, that means one of you guys probably knows how to fix it.
A couple of months ago, I installed Linux Mint alongside my Windows 8.1 without any issues, the dual-boot worked perfectly. Mint didn’t seem to agree with my computer very much though, the keyboard and touchpad would often stop working out of nowhere, it was really annoying, so I decided to switch distros, and I picked openSUSE.
Now, from what I understood, all I had to do to switch from one Linux distro to another was tell the installator to format the same root partition I had already established but to mount from the home and swap partitions without deleting anything. The OpenSUSE installator seemed to understand that all on it’s own, so that part was pretty easy…except that now it won’t boot.
To be honest the whole UEFI/Legacy booting thing always confused me, but I managed to get dual boot working quite nicely the first time around. Now, when I turn on the computer, it goes straight to grub. If I hold F12 while it’s booting and go into booting options, I’m able to see, under UEFI booting, that there are still three options: two of them are named ubuntu (which is a little strange considering I’ve never actually installed ubuntu but I assume this happens because Mint is one of Ubuntu’s children) and the third is windows boot manager. I was pretty happy to find Windows still works if I select that option, which is where I’m typing from right now, but either one of the ubuntu options only takes me to grub. In conclusion, Windows is here as long as I hold F12 while booting, Mint is gone, and openSUSE is literally nowhere to be found. Does anybody know what caused this/how to fix it?

Thanks very much, anyway!

Hard to say exactly but if you get to a grub menu Is it a openSUSE grub or the one from Mint??

When you installed did you be sure to boot the install media in EFI mode? Did it install grub2 or grub2-efi?? In EFI mode it should alos mount a small efi boot partition (which is already there if other OS’s) as /boot/efi and the file system is FAT. In that FAT partition there will be an openSUSE director with the openSUSE boot stuff. In addition the entries in the EFI flash memory are added for the OS. Since you don’t see these I assume you booted the Installer in legacy (MBR/MS mode). Note that any other entries are not automatically removed in the efi boot or the EFI memory.

So won’t boot covers a lot of ground. Do things start and just freeze maybe with blank screens. Since we can’t see over your shoulder you have to be very explicit

  1. Are you not able to boot in both windows and openSUSE or only one of them?
  2. Did you change boot option, Legacy or EFI?

Thanks very much! I was actually able to fix this already, it was only a matter of switching from UEFI to Legacy. Mint used to boot through UEFI so I assumed openSUSE would do the same, but apparently that wasn’t the case.

Sure it will openSUSE fully supports EFI booting. But if you boot the installer in legacy mode rather then EFI then it will install in legacy mode. You must press F12 at boot or what every your hardware wants to get to the boot menu when you boot the Installer there you can select the mode. Also some EFI’s have a setting to how removable media should default boot. Mixing mode ie one OS booting one way and another booting another way leads to potential problems and confusion.