By following these steps and tips, you should be able to successfully download and install macOS High Sierra 10.13.6 ISO on your Mac.
: You can find manual "Update" or "Combo Update" files on the Apple Support Downloads page
Elias felt a cold draft. He looked around the server room. The rows of black server racks were gone. In their place were wooden shelves lined with bulky iMac G3s and Power Mac G5s, all humming in unison. He was no longer in the university basement. He was in a digital construct of the operating system itself.
The fluorescent lights of the university server room hummed a monotone B-flat, the soundtrack to Elias’s thesis project. It was 3:00 AM, and the deadline was in five hours.