mac high sierra updates not installing on raid hd

Thank you so much, and hopefully in a week or two I'll have a happy update. 'When you hear hoofbeats, think horses, not zebras.' I won't look for an OEM graphics card unless I'm really out of ideas, and I bet your hunch that it's my hard drive is correct. Luckily I work for a company that uses Macs, so I'll ask if I can borrow a OEM drive and try that out first! A lot of threads I've seen walk through the process (again, thank you for pointing me that direction!), so I'll refer to those for the nitty-gritty details and troubleshooting once I have an OEM drive. (I made some USB installers with both, just in case) If necessary, reformat your SSD to Mac OS Extended (Journaled), not APFS Try setting up another admin user account to see if the same problem continues Boot up your Mac using Cmd + R to access the recovery partition. I've been focusing on High Sierra since it's older, but both versions would allow me to run the most up-to-date software. Try restarting in recovery mode and install macOS High Sierra or Sierra from a bootable USB drive disk. (I know newbies can be frustrating to deal with, and it means a lot to me you're taking the time to help!)

Click to expand.Firstly, thank you so much for being patient and explaining things out! This is such a great learning experience.

Mac high sierra updates not installing on raid hd