Problems updating mac os with windows
If the installation is truly frozen, you may need to reinstall mac OS High Sierra via Recovery Mode, by rebooting the Mac and holding down Command R and then choosing to reinstall mac OS.
This is rare, but there are some reports the installation of High Sierra fails.
APFS support is not currently implemented for Fusion drives or HDD drives in mac OS High Sierra versions, but Fusion and HDD support for APFS is expected to arrive in a future software update version.
Try rebooting the Mac and running the High Sierra installer again, or if you have a mac OS High Sierra USB boot installer drive, run the installer from there.
Reboot the Mac, then attempt to re-install Mac OS High Sierra using the “Install mac OS High Sierra.app” app again.
This should resolve most issues with failed installation attempts.
Some Mac users are encountering an installation error stating “Installation of mac OS could not continue. Try again later.” Troubleshooting this issue usually involves multiple easy steps: confirming the Mac has active reliable internet access, and then trying to install mac OS High Sierra again.
Installation requires downloading important content. Sometimes a reboot can be sufficient to remedy this error as well.