First, take a backup (to an external disk!) of everything that is important to you! Note that operating systems can easily be installed, but your personal data can’t be restored without a backup. This is the most important step!
Second, make sure you have an Antergos USB installer stick, you’ll need it later.
The rest is up to whether your system is using UEFI boot or BIOS/Legacy boot. So which is it? You can find it out with command
If that shows an error about missing files/directories, then it is not UEFI.
Note that you may need to update your BIOS/Firmware if there are strange problems with the installation.
And could you show the output of
When reporting issues, please do not hide the details! ;-)
Show files here: cat "file" | curl -F [email protected] https://ptpb.pw/?u=1
and show the URL.