Send logs: https://forum.antergos.com/topic/10586/eat-logs; install eat: wget -q https://github.com/manuel-192/eat/raw/master/PKGBUILD && makepkg -sic
Please don't hide information when asking for help.
Right, now I think I remember that BIOS update thread.
True, installing Windows for just this one task is a big job.
To make it less problematic for the installed Linux, if you happen to have another (empty) disk available, you could temporarily remove the linux disk and connect the empty disk for installing Windows… Then Linux would be safe from any potential issue.
But this is just a thought, and upgrading BIOS doesn’t even guarantee anything.
Sorry I couldn’t help you solve the original issue. But that’s just life sometimes.
I’d say Antergos reinstall is the quickest way to solve the issue.
Your disks are a bit mixed, it is not recommended to have both gpt and msdos partition tables mixed on the same system. And your machine seems to have Windows installed in BIOS legacy mode, and somehow Antergos installed in UEFI mode. Maybe you have installed Antergos on a different machine, and later just put the disks into the same machine?
First backup your important data files (from both disks!) to an external drive before doing anything more.
Then, if you really want to make sure to have Windows working, create a Windows rescue/recovery disk (that can help you restore Windows booting).
Then you need to find out if your machine supports booting in BIOS legacy mode. That is the default on old machines, but UEFI mode is the default on new machines. There are also machines that support both modes.
If your machine does not support BIOS legacy mode, stop right here, don’t continue with these instructions!
So, on a BIOS legacy system, modify your current Antergos disk with gparted to have the msdos partition table. This will delete everything on that disk.
Then install Antergos in BIOS legacy mode, not UEFI mode. Make sure the installer stick boots in BIOS legacy mode.
And let the installer write MBR to /dev/sda (which probably is the Windows disk). However, make sure the installer is not writing MBR to the installer stick!
Actually, as an advanced thing, MBR could be written to another disk as well, but that depends on how your machine selects which drive to boot from.
Next time, please use the </> button at the top of this writing area around your output. It makes the output much more readable.
So it seems Antergos is installed on partition /dev/sdb2, right? Note that you need to have the correct partition here, otherwise it will never work.
If so, then you would chroot to it like this:
sudo mount /dev/sdb2 /mnt sudo arch-chroot /mnt
and then you are (or should be) in the installed system, and give most normal commands there.
By the way, what does your system say when you try to boot? Is there any error message, or what exactly happens?
OK. Sounds like your machine (hardware) has some rare issues.
Basically Antergos (and any other decent operating system) should work without such issues.
But your machine has a Ryzen processor, right?
This thread is already quite long, TL;DR, but have you tried updating your machine’s BIOS/firmware? If not, and if there is an update available, that just might help (or not). But be careful to have the exactly right BIOS/firmware for the machine if you would be considering an update.