Step 2: As soon as it is ready, an automatic system scan or checkup will occur. In most cases, mounting is an automatic process that happens as soon as the hard drive is connected to a Mac or MacBook Pro. To stop excluding an item, such as an external hard drive, select the item and click the remove (–) button. 10 (and higher) and Windows 7 (and higher). External Hard Drive Not Mounting on Mac Is Fixable, Go and Make It Work Now. Step 2: Click the ' Edit ' button from the security tab.
Make sure to back up all data before erasing the disc. How to force mount an external hard drive mac This will load up OS X Recovery.
