I need to downgrade from Mountain Lion to Lion....

[Berek]

I've searched everywhere.

I have ML and I want to go back to Lion, mainly because I'm a student and there is a program called Examsoft that I need to run for exams. There is a ML version but the only reason I can't use it is because my school needs to upgrade their software on their end for it to work. It's a long story and I don't want to bore you guys. I just need to downgrade to Lion. That's it.

I bought a MBP last May that came with Lion pre installed. When ML was released I upgraded. I tried to reboot with OPT CMD and R and saw the Lion software come up. However I couldn't reinstall because it said a newer version of the OS is already installed.

Please if you have time, provide me with a step by step procedure to get Lion back. I know it may involve reformatting and I'm ready for that. I have no backup image with Lion and I dont use time machine because all my important docs are on Dropbox. I don't really use the HD space for anything except WoW and iTunes as needed. Thanks in advance.

 

[Weaselboy]

Since your machine came with Lion, the serial number is tied to Lion and a clean install from Internet Recovery will get you Lion from Apple's servers.

To get there though you need to erase both Macintosh HD and the hidden Recovery HD.

Use this utility from Apple to create a Lion Recovery USB key. Afterward do an option boot and point to the USB key to boot. This will run recovery from the USB allowing the entire drive to be formatted killing Mountain Lion and its Recovery HD.

Start Disk Utility from the USB key and click the drive brand name at the top left... like "Toshiba 128GB" or whatever. Make sure you have selected the drive itself and not the Macintosh HD partition. Now erase the entire drive formatting as Mac OS Extended.

Once that is done quit the install process and reboot into Internet Recovery by doing a command-r boot. This will boot from the system firmware (EFI) and take you to Apple's servers to first download the Recovery HD then afterward the fill Lion install.