How can I uninstall OS X Yosemite and return to OS X Mavericks?

I just updated to Yosemite on my iMac mid-2010 and realised my Archicad 15 software/program won't work as it isn't compatible. I do not have any external time machine back ups and need to know how I can uninstall yosemite and go back to Mavericks? Can i just go to my purchases tab in the app store and re-download Mavericks?

Also A folder which contained all my .pln files (archicad saved documents) suddenly disappeared after the yosemite upgrade (which also caused huge problems with the blank white screen, but I have already overcome that issue) but am currently still trying to recover those files.

Any help in finding those files or reverting back to Mavericks would be highly appreciated!!

I would doubt that you will get any files back that have been somehow deleted yet failed to be backed up. You will need to erase your HardDrive completely before reinstalling an older OS X, and you will do that by holding down Command + R upon booting nd following the prompts (after of course erasing the HardDrive with Disc Utility.

Cheers

Pete

Can i just go to my purchases tab in the app store and re-download Mavericks?

Unfortunately, not as you cannot install an earlier OS over the top of a later OS - unless you erase your hard drive first. And, unless you can find your lost files in a folder named "incompatible apps" or some such, they are gone (you can try a file recovery software or company, but that would mean that you cannot use your computer at all until after they try to recover the files) - make sure you maintain backups from now on

I just joined thread, but would actually like to downgrade from Yosemite to Lion so I could install ProTools 8/9 again. I just purchased a brand new MacBookPro 15" (2015) but it isn't compatible. I cannot afford to pay $700 for the new ProTools 11.3 which is the only version compatible with Yosemite. What is involved and do I risk losing any data?

If it is a brand new MBP, then you cannot boot from anything but the OS version it came with (or a newer version) - which, presumably, is Yosemite. Macs cannot boot from an OS older than what they came with.

You'd have to find yourself a used/refurb machine from about late 2011 which could run Lion - here is a list of builds/OS versions:

Mac OS X versions (builds) for computers - Apple Support

Thank you. I have a 2007 Mac Mini that I just sold to SIs in Law because I got this new MBP. Will have to search around to, perhaps on Avid (protools) forum to see wht other options I have with their software.

Thank you very much!!! I really didn't want to do it. Something inside of me felt that doing that with my brand new machine would be compromising it in someway.

Well, you could update that Mini to Lion (if it isn't running that already) and keep it - that might be worth it if that software is that expensive.

Yes, it already has Lion installed (the newest OS it would accept on that Mac Mini) but I already sold it to her. Thank you. I appreciate the info.

I have tried Kappy's method 3 times, it tells me it is downloading some additional software, makes me wait around 4 to 5 hours... and then sends me to the yosemite home, like nothing happened.

I tried to use time machine, but does not work.

I tried to use the original cds that came with the macbook, but nothing...

Does anyone else have any other suggestions?

I am a teacher, and since upgrading to Yosemite, I cannot utilize my textbook's resource disc, because it is no longer supported by the operating system. This disc has all of my class's assessments on it. I also cannot access previous, or create new lessons using my Smartboard application software. It claims I need to upgrade that software, which the school cannot fund, (it requires a new license in order to do so). And I also have to reconnect to my WiFi every time I want to use the internet. Yosemite has just made my job so much more difficult & frustrating.

Reinstall the backup you made of your previous system, when it was working with your required Software. When using such software which has vital connotations to one's work, it is important to be careful updating Operating Systems. Many professionals I know install the new OS X on a test partition and test their software against it before installing it on their main partition.

But your backup should save you from this predicament, as it is meant to.

Cheers

Pete

I Have a late 2011 MacBook pro and same once yosemite been installed it's been so slow and unresponsive and unfortunately I have no back up of Maverick. I am hoping I can go back or Apple get a fix as I was beginning to actually think it was my Mac.

Go to the App Store where you originally got Mavericks from, download it again (might be in Hidden Purchases) and then erase your Hard Drive and reinstall it. Easy really. Back up your data as it will all be removed when you erase the drive. Or perhaps try trouble shooting your Yosemite Install by opening a new Topic and posting an etrecheck report.

Pete

HI kappy,

i followed instructions below to the point where I should get Recovery main menu but only thing I get is globe/black triangle and top of it is exclamation mark, and nothing happens after that. what should I do to get Recovery Main menu?

in past two week my MacBook has freeze multiply times I was able to recover it couple of times and it's keep crashing after couple of days. I read on support side to turn off FireFault etc and problem still coming back (freeze/crash).

i reinstalled Yosemite couple of times and same thing happens every time.

this whole thing started after I updated to Yosemite, needles to say all data I had on hard drive was lost, but be as it may, I would like to start from zero with Mavericks but to get there is a problem.

any help or guidance you could give me

JsT

:

Install Mavericks, Lion/Mountain Lion 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:

1. Select Disk Utility from the main menu and click on the Continue button.
2. 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.
3. 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 Lion/Mountain Lion. Mavericks: Select Reinstall Lion/Mountain Lion, Mavericks 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.

i'm trying to go from yosemite back to mountain lion on my macbook air

there was no "mfgr.'s ID and size" just an icon of a drive called Mountain lion and underneath the line 'disk 1' and underneath that OS X Base System.

I tried Disk 1, and Partition, but there is no "Volume Scheme heading"

Pictures would go a long way here : )

Thanks,