Problem
When you turn on your Mac computer you see a prohibited no entry sign and are unable to go any further.
Solution
Reset the PRAM / NVRAM.
If that doesn’t work then reinstall Mac OS X.
Knowledge base for Windows, Mac & Assistive Technology.
Knowledge base for Windows, Mac & Assistive Technology.
When you turn on your Mac computer you see a prohibited no entry sign and are unable to go any further.
Reset the PRAM / NVRAM.
If that doesn’t work then reinstall Mac OS X.