Linux

@Rubanski If it's booting into emergency mode, there are usually one of three issues, kernel is corrupt, a file system can not be mounted read/write, and this can be because of file system corruption or in the case of mdraid, because a raid device failed to self-assemble, or initramfs is broken. The easy way to fix most of these is to use an automated utility called boot repair, you download the ISO then burn to a thumb drive, then when you run into this kind of problem boot off the thumb drive. I'd start by trying to determine which of these it is, if you get into emergency mode then you at least have a shell prompt, try typing dmesg to see if there are any errors relating to the kernel, then check if all of the partitions are mounted and if they are all mounted read/write. If one or more is mounted read only this usually means that the automatic fsck found errors it can not fix and needs a manual run, in which case try fsck -f -y /dev/sdxx or /dev/nvmexnxpx, which ever the case may be (hard drive verses SSD). If this was the issue after the fsck successfully repairs the file system you should be able to boot successfully. If not, and nothing kernel related shows up in dmesg, then probably your initramfs has gotten hurt. In this case since you are new to Linux, boot repair is the easiest way to fix it. You can also fix manually but that is more complex, however if you need instructions on how to do this let me know and I will elaborate. Even doing so manually though requires another bootable Linux media, does not have to be boot repair, a popos install USB will also do.