Yosemite
How to uninstall Yosemite
MacBook Pro (15-inch Late 2011), OS X Yosemite (10.10)
How to uninstall Yosemite
MacBook Pro (15-inch Late 2011), OS X Yosemite (10.10)
Erase the hard drive then install an earlier version of OS X or restore the backup of your previously installed version.
Install OS X Using Internet Recovery
Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.
Boot to the Internet Recovery HD:
Restart the computer and after the chime press and hold down the COMMAND-OPTION- R keys until a globe appears on the screen. Wait patiently - 15-20 minutes - until the Recovery main menu appears.
Partition and Format the hard drive:
- Select Disk Utility from the main menu and click on the Continue button.
- After DU loads select your newly installed hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
- Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed. Quit DU and return to the main menu.
Reinstall OS X: Select Reinstall OS X and click on the Install button. Be sure to select the correct drive to use if you have more than one.
Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.
This should restore the version of OS X originally pre-installed on the computer.
How to remove Yosemite and install back Mavericks? Or is there a patch for Yosemite?
Ever since updated to Yosemite, my iMac does not recognize blu-ray discs on my Samsung Blu-ray burner any more, it does not matter which software I use, not even Yosemite Utility. It still recognizes DVDs. However, DVD movie quality is terrible compare to Blu-ray.
I used to be able to create movies using Final Cut Pro X and burn Blu-ray discs on my Samsung blu-ray burner. I could use Toaster 11 to burn blu-ray discs also. Not any more.
I have beautiful large movie files created using Final Cut Pro X. I can no longer share these files. They can not get on Blu-ray discs nor on USB flash drives to view on TV. What a pity!
PLEASE HELP!!!!!!!!!!!
You no longer can download Mavericks. Were you to downgrade you would have to purchase Mountain Lion. Unless you still have the Mavericks installer application, you cannot install Mavericks.
I am glad that you are helping me. You are at level 10.
Some one just told me that something might go wrong while upgrading to Yosemite. He suggested to backup my iMac and install Yosemite again. He mentioned he did not have trouble with blu-ray with Yosemite.
About downgrade, I don't think I have Mavericks or Mountain Lion any more. Apple took them away while upgrading.
Can downgrade be successful? Will I open a whole can of worms? Will it affect Final Cut Pro X and other programs which have been upgrading few times since Yosemite came in?
I have two partitions on my iMac now. One is for Windows. Do I have to make the whole installation from scratch?
Currently I am working on backing up my iMac. Either way I have to back up my hard drive. It will take some time.
What is you opinion?
Best Regards,
In many cases users have problems after installing Yosemite because the system they upgraded was in a dysfunctional state. Although you certainly can do as suggested It may not be necessary if you are upgrading Mavericks. In my opinion you may only have to do the following. But, if that does not work to solve your problems, then installing Yosemite from scratch may be needed.
Reinstalling OS X Without Erasing the Drive
Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Reinstalling OS X Without Erasing the Drive
Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.
When the recovery menu appears select Disk Utility and press the Continue button. After Disk Utility loads select the Macintosh HD entry from the the left side list. Click on the First Aid tab, then click on the Repair Disk button. If Disk Utility reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit Disk Utility and return to the main menu.
Reinstall OS X: Select Reinstall OS X and click on the Continue button.
Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.
Alternatively, see:
Reinstall OS X Without Erasing the Drive
Choose the version you have installed now:
OS X Mavericks- Reinstall OS X
OS X Mountain Lion- Reinstall OS X
Note: You will need an active Internet connection. I suggest using Ethernet
if possible because it is three times faster than wireless.
Wow, you know so much!
I was told just go to purchased, choose Yosemite, disregard it was installed, install it anyway. Will that work? So back up is just a precaution?
Thanks so much.
Best Regards,
Not through the procedure I listed. It will offer Yosemite automatically for you then request the Apple ID you used to get it originally. However, should you simply wish to download a copy, then you can do so from your Purchases list in the App Store. Note, that if you already have Yosemite installed, then it may not let you download it.
Backup is just a precaution. Unexpected things can happen.
Great! Thanks a lot! I can not wait to try! However, backup is still going slowly. (I have some large 2-hour movie files created using Final Cut Pro X.)
I shall let you know the result.
Best Regards,
Hi, Kappy,
I reinstalled Yosemite through Purchases List in the App Store. However, it still does not recognize Blu-ray discs. I am afraid it is just the problem Yosemite brings in. What do you think? Can you have Apple fix this big bug?
If my iMac can not burn Blu-ray discs, it is a trash for me. I will have to go back using my old HP Windows, at least it still burns blu-ray discs. Or I will have to install Mavericks. I found Mavericks still in my Purchased List. Will it work since I have upgraded Final Cut Pro X and other programs few time since Yosemite? Do I have to wipe out the whole hard drive? I have two partitions currently, one for Windows and the other of iMac.
PLEASE HELP!
Thanks you very much.
Hi, Kappy,
I reinstalled Yosemite through Purchases List in the App Store. However, it still does not recognize Blu-ray discs. I am afraid it is just the problem Yosemite brings in. Roxio newest Toast 14 only burns DVDs not Blu-ray discs any more. Can this be a hint that Yosemite can not recognize Blu-ray discs? What do you think? Can you have Apple fix this big bug?
If my iMac can not burn Blu-ray discs, it is a trash for me. I will have to go back using my old HP Windows, at least it still burns blu-ray discs. Or I will have to install Mavericks. I found Mavericks still in my Application folder. Will it work since I have upgraded Final Cut Pro X and other programs few time since Yosemite? Do I have to wipe out the whole hard drive? I have two partitions currently, one for Windows and the other of iMac.
I just downloaded Mavericks. The pop up box mentions: This copy of the "install OS X" application is too old to be opened on this version of OS X.
PLEASE HELP!
Thanks you very much.
I was unaware that OS X had any Blu-Ray capability without the use of third-party software. Are you sure you didn't use third-party software to burn Blu-Ray discs?
If you still have the Mavericks installer then you can reinstall it but be sure to make a copy in your downloads folder for safe keeping. The error message is probably because you are trying to open the installer while running Yosemite. You will need to install an earlier version of OS X then upgrade it to Mavericks.
Hi, Kappy,
I have Final Cut Pro X video editing program. That is the reason I bought iMac. I edited few movies and successfully burned to Blu-ray discs using Final Cut Pro X under Mavericks. I also have Roxio Toast 11 which burned Blu-ray discs under Mavericks.
Nothing works with Blu-ray discs any more under Yosemite. Please verify. Roxio newest Toast 14 only burns DVD not Blu-ray discs any more . Can that be a hint that Yosemite does not recognize Blu-ray discs?
I tried to reinstall Mavericks while I have Yosemite now, that is where the error message came out. Right now Mavericks is only in my Purchased List, not on my system. I am afraid if I wipe out the hard drive and install Mavericks, my Final Cut Pro X and other programs which have been upgraded few time under Yosemite will cause problem.
By the way, I did as you instructed, boot to Recovery HD and repaired HD. Only one thing it can not repair: SUID file "System/Library/Cores...." has been modified and will not be repaired. What is that?
Thanks for helping me.
Best Regards,
It has always been my understanding the there is no Blu-Ray support in Macs because Steve Jobs would not permit it. Any Blu-Ray support had to come from third-party utilities. But I've been wrong before. 🙂
The SUID message in Disk Utility is innocuous. Ignore it. OS X Disk Utility's Repair Disk Permissions messages that you can safely ignore.
Hi, Kappy,
Thanks for letting me that I can ignore SUID message. You know so much.
I thought Final Cut Pro X was Apple software.It worked under Mavericks. Roxio Toast 11 worked too.
Is Apple taking away Blu-ray burning?
Will you think if I wipe out the whole drive and install Yosemite from scratch will work on Blu-ray discs?
OK, I was apparently wrong. See this OWC article about burning Blu-Ray discs on a Mac.
Yosemite