Reverting a failed Yosemite upgrade

[MRBisMe]

Hello,

I looked and I haven't seen a thread matching this exact case. I have tried to upgrade my iMac to Yosemite and it just hung during installation. Trust me, it truly did hang. I read a lot of forum postings that said be patient. I was patient for 72 hours then I gave up and finally shut it down. However, I am not sure what to do from here. I see a couple options:

1. Boot to an external drive (I already have Yosemite on an external drive), copy everything from my internal drive to an external drive and then install Yosemite fresh on the internal drive. Afterwards, copy the applications and documents that I saved off back. I know this will work. However, I prefer to leverage TimeMachine backups if I can and this is where I need guidance. Will option 2 work?
2. Do option 1, but instead of copying apps and documents to an external drive, once I have installed Yosemite on the internal drive, restore apps and docs from TimeMachine. Will this work given the backup was created with a different version of the OS? My guess is that it would, but I want to be sure obviously.

Any guidance and/or other options will be much appreciated.

Cheers,
Michael

 

[Significant1]

72hours sure was a lot of patience! What happens if you just turns it on and let the installation resume. Does it still hang?

Option 2 will work and the one I would recommend. Doing an extra backup as in 1, cannot harm, in case Your timemachine backup is broken or not up to date.

 

[MRBisMe]

72hours sure was a lot of patience! What happens if you just turns it on and let the installation resume. Does it still hang?

Option 2 will work and the one I would recommend. Doing an extra backup as in 1, cannot harm, in case Your timemachine backup is broken or not up to date.

Wow, I didn't even think to look what would happen if I just tried to resume. So, I turned it back on and it seemed to be fine!! I just assumed the worst! Cheers.