How can I delete previous os from my macbook?

Hi folks please kindly let me know that how can I delete my previous outdated version mac os data from my macbook?

Posted on Mar 14, 2022 1:24 AM

Similar questions

How do I wipe all data off of Mac mini 2010 to install a newer macOS? How do I wipe all data off of Mac mini 2010, so I can install newer version? [Re-Titled by Moderator]
906 2
Update I erased my macOS Monterey 12.5.1 And now I have the old version macOS High Sierra 10.13.6 How I get back my macOS Monterey 12.5.1?
1034 7
Upgrading past 10.6.8 I want to upgrade my mid 2010 Mac Pro's 10.6.8 Snow Leopard to, say, 10.11 El Capitan (please don't ask why I haven't ever done this till now). According to Apple's "How to create a bootable installer for macOS" (HT201372) I can download the El Capitan package installer to install "Install OS X El Capitan.app" into 10.6.8's /Applications, and then use its createinstallmedia tool to create a bootable 10.11 installer on to a flash drive. Then I can use that installer to upgrade (a copy of) my 10.6.8 to 10.11. I haven't tried this as yet because my main concern is if I don't want to use the result how can I revert back to my 10.6.8? As I said I would do this to a copy of my 10.6.8 drive and ideally if I wanted revert I simply boot from the original 10.6.8. But what has me concerned is the line in that HT201372 doc (under Learn more near the end) which states: "A bootable installer doesn't download macOS from the internet, but it does require an internet connection to get firmware and other information specific to the Mac model." So an installation changes some of my Mac Pro's firmware, presumably the stuff that affects the boot. So do I assume that I cannot simply boot back my 10.6.8 once I've done one of these installs beyond 10.6.8? If this is the case then one way I can think of to revert the firmware is to install the original 10.6.4 installer CD (assuming it still mounts, haven't taken it out of the closet for over 10 years) to revert the firmware done by that install? And yes, I know you have to change the clocks back to about 2012 to do that. A much simpler way, if it is possible, is to use some terminal command with appropriate arguments to revert the firmware (nvram?). If so what would that command look like? Bottom line, I don't want to "upgrade" (?) beyond what I got until I am sure I have a backup path in case this doesn't all work out. Any help/suggestions would be appreciated.
1026 1

1 reply

Mar 14, 2022 1:31 AM in response to katiewhitehats

Please let me know if anyone have the solution.
Thanks

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

How can I delete previous os from my macbook?

Welcome to Apple Support Community

A forum where Apple customers help each other with their products. Get started with your Apple Account.

Learn more Sign up