Trouble reinstalling Mac OS

[John Takami]

Older MacBook A1342. Tried to wipe Mac clean since having slow down trouble. When I try to re install MacOS Sierra. It shows disk locked ?

 

[Sam784]

I am wondering if installing Mac os will be the same as installing Windows os? Is it possible to do this with the help of an installation disk?

 

[theapplehead]

Older MacBook A1342. Tried to wipe Mac clean since having slow down trouble. When I try to re install MacOS Sierra. It shows disk locked ?

Are you certain you properly erased your Mac? Be sure you selected “show all devices” in disk utility. Then erase the one at the top which holds the other volumes. Format it as APFS GUID map scheme. And then you should be able to install macOS. Try that and report back. Cheers!

 

[4sallypat]

Even formatted with Mac OS Extended (Journalled) / HFS+, High Sierra should still work - my old first gen Macbook has High Sierra which is in HFS format.

Try this:
While in the Recovery partition or Internet Recovery mode, go into Terminal and change the date using a terminal command to a date in 2018.

I found that if the date changed to 2018, High Sierra will install without a hitch.....