I ran OS X 10.7 latest version on my MacBookPro 2011.
Then I installed on an external USB stick 10.10.3 from my running system OS X 10.7.
The installation on the stick was successful.
After testing 10.10 for some minutes I restarted the system, took of the usb-stick and wanted to restart from my internal disk the 10.7 system.
However, now there is the installer and insists on installing 10.10, what I do not want to do.
The disk utility says that my internal disk is not writable and that I cannot modify it.
Starting with an external disk with 10.7 works, but does not allow to reactivate the internal disk.
Recovery with Cmd ⌘ R loads 10.7 via the internet (it therefore still know that the original system is 10.7), but I cannot recover the 10.7 system, since I cannot write to the internal disk.
The internal disk is now Master Boot Record partitioned.
I do not know if it was GUID before or not: At least it worked for three years before.
I have a backup, but since this is 1TB I do not want to load it via a USB 2.0 port.
How can I reactivate my internal disk with 10.7? If reasonable I would change to 10.8 (but not higher) if there is a utility that works with 10.8 only. Any proposal or links to tool to remove the OS X installer and allow me to restart from my internal disk with 10.7?
The output of
gpt -r show /dev/disk0:
sudo gpt -r show /dev/disk0 results in: start size index contents 0 1 MBR 1 1 2 1466246608 1 MBR part 175 1466246610 1 1466246611 487278557 2 MBR part 175
I have a time machine backup.