I am trying to install Lion on a Power Book Pro that already has Yosemite install for a duel boot system. The main Application I am installing wont run on Yosemite. When I try to install Lion I get a circle with a slash though it and it won't install. Please help!
MacBook Pro, OS X Yosemite (10.10)
You will have to erase your Mac and then install Lion.
You do not have a Powerbook, you have a Macbook or Macbook Pro. Power books can't run Lion, or Yosemite.
You will have to erase your Mac and then install Lion.
You do not have a Powerbook, you have a Macbook or Macbook Pro. Power books can't run Lion, or Yosemite.
What operating system did your Mac come with when it was new? In general you can't install an OS on a Mac earlier than the one it originally came with. If it came with Lion then Csound1's advice applies. If it came with Mountain Lion, Mavericks or Yosemite you are won't be able to install Lion.
What year is your Macbook pro from........??
Technically its possible to downgrade to an OS X version on a Mac than the OS X version it came with originally. I can also suggest you many ways to do so.
BUT READ THIS
Don't install a version of Mac OS X earlier than what came with your Mac - Apple Support
If your Macbook pro is from the year 2010 (Snow Leopard preinstalled), then its worth to downgrade it to Lion from Yosemite as you have already installed Yosemite.......
Hope this helps.....
I purchased another hard drive and did a restore of Lion from the internet. This preserved my copy of Yosemite. Thanks!
Installing an Older Mac OS that has a Newer OS
