How to reset PRAM/NVRAM on OS X Mountain Lion?

kreiley

How do you reset the Parameter RAM / Non-Volatile RAM on a Mac running Mountain Lion? I've had a couple start-up crashes this week and want to give it a try before I just reinstall OS X. Thanks!

Answer this Question

Answers

3 total
jlister
Vote Up (18)

You can zap your PRAM/NVRAM by restarting your machine and pressing Command+Option+P+R. Make sure to hold keys down until it restarts. I would continue to do it until it restarts again, but I'm honestly not sure whether there is any benefit to doing so or if it is an old Mac wives tale.  

lmile61
Vote Up (17)

You need to reinstall the OS and if some important data then difficult to restore after reinstalling.I think there is no another way.

 

jimlynch
Vote Up (13)

This support article from Apple should help:

OS X Mountain Lion: Reset your computer’s PRAM
http://support.apple.com/kb/PH11243?viewlocale=en_US&locale=en_US

"A small amount of your computer’s memory, called “parameter random-access memory” or PRAM, stores certain settings in a location that OS X can access quickly. The particular settings that are stored depend on your type of Mac and the types of devices connected to it. The settings include your designated startup disk, display resolution, speaker volume, and other information.

Note: To print these instructions, open the Help Viewer’s Action pop-up menu (looks like a gear) and choose Print.
Shut down the computer.
Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
Turn on the computer.
Immediately press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
Continue holding the keys down until the computer restarts, and you hear the startup sound for the second time.

Release the keys.
Resetting PRAM may change some system settings and preferences. Use System Preferences to restore your settings."

Ask a question

Join Now or Sign In to ask a question.
Red Hat has developed a version of the Linux operating system that can be used to test chips and associated hardware based on the ARMv8-A 64-bit architecture for servers with the aim of standardizing that market.
State-run media ratchets up the rhetoric after sudden swoops into Microsoft offices Monday.
Pushbullet is great for quick and dirty file swapping between your Windows PC and Android.
You probably didn't know you needed a color-coded goal manager or a dedicated email tracker.
Officials today from the China government appeared at four Microsoft offices, but the purpose of the visits was unclear.
Percentage of former and current workers who approve of CEO drops by 24%, those who disapprove quadruples, after big layoffs hit.
Look to Vista for how Redmond will treat Windows 8 as it moves on to the next bright, shiny OS.
As with previous versions of OS X, it's not difficult to create a bootable installer drive from the Yosemite beta installer, though the processes have changed slightly since Mavericks.
If you've leapt aboard the beta without thinking carefully about what this would mean for day-to-day use, and you now wish you had Mavericks (OS X 10.9) back, we're here to help.
A new model of the Raspberry Pi is out, but it's not Raspberry Pi 2
Join us:
Facebook

Twitter

Pinterest

Tumblr

LinkedIn

Google+