Yosemite Install Woes

Question

I am hoping someone will be able to help please, after three days of battling an upgrade that went wrong. I've documented this as fully as I can since I see a lot of comments from people trying to help here asking for specific steps that we (those of us with the problems !) have undertaken. Sorry if its a bit long :
I have a 27" iMac 2010, and I think it was running OS X Lion or Mountain Lion (can't see anymore !). In retrospect I'm not sure if this was the correct upgrade step, but I tried to upgrade directly to Yosemite over the weekend, and after completion the Mac rebooted straight into Recovery mode. The internal  Macintosh HD SATA Drive was locked, even though I did not have File Vault switched on. I was able to unlock it by first selecting it as a reboot drive, unlocking it and then going back to the Recovery screen to select Time Machine Backup. However, my Time machine backup, on a WD My Book Live Duo, failed to work - the OS could not see a valid TM backup. It was at this multiple failure point I began to show some signs of slight worry...........
So, I tried to download OS X Lion from the internet (Recovery mode option). The download worked for the US Store only (not UK where not available), but still failed to boot in anything but recovery mode.
I tried Command -R, Option boot etc etc but still the same recovery screen appeared.
I then went into Disk Utils and saw that my Macintosh HD with all my data was greyed out and showed a locked logical partition. I tried to get around this by re-selecting it as boot drive, unlocking it and then returned to the Disk Utils window. This then showed it as a verified SMART drive. I verified the disk and repaired any broken links etc. Still it would not reboot into anything but Recovery Mode, reverting again to a locked logical partition for the Macintosh HD internal SATA drive after each reboot.
So I then unlocked it as before, and tried to Option- turn off Encryption in the File Menu. An error message stated that it was unable to turn off encryption.
I'm thinking I'm stuck....then I went back into the Terminal Window and accessed the /dev that is the Macintosh HD SATA drive. Under /Users/username all my data was there intact !.
My last step was to go back to Disk Utils, hook up an empty 2TB external WD elements drive and then select it as Restore Drive for the Macintosh HD. It took 20 hours but all the data (not Apps) was copied to it. So at least I got the data.
I could now completely erase my HDD and start again afresh, but if I could find a way of getting back in so I can see if I could at least solve the problem, since it doesn't seem to me to be a hard drive failure issue, but more of an OSX installation error. Is there any solution that you  are aware of that could get me back to a position where my Macintosh HD could reboot and allow me access to my files and maybe even try to figure if I can restore what I thought was Time Machine via the OS-X. I don't want to just trash the drive before understanding if it can be at least restarted.
Thanks very much
Paul

Answer 1

That's the issue - I'm not able to actually click on anything. I'm able to enter my password for my Apple ID, but cannot get past the terms and conditions page. When I've tried to click accept to move on, the system won't let me because the accept button is grayed out. I've now tried to reboot at least ten times, and each time I restart, I get a message that says something along the lines of "you shut down because of a problem. To restart the programs that caused the problem, click ok." When i try to click cancel instead, I'm unable to do that either, and it takes me into this loop.
I've to single click, right click, left click, double click - everything - and nothing works.
On the restarts, I've tried to boot into recovery mode, and that isn't working either.  Is my only option taking it in somewhere to have it fixed? Clearly what I am doing here at home isn't working, and I'm not Mac savvy enough to fix it on my own.