How to fix error in Mac OS X El Capitan and Yosemite: "This copy of Mac OS X can't be verified."

In this video, I will show you how to fix an issue that occurs when trying to reinstall or install a fresh copy of Mac OS X Yosemite or El Capitan. It says "This copy of the Install Mac OS X can't be verified. It may have been corrupted or tampered with during download.

Hope this helps and you can fix this issue!