Chameleon gone after crashing, how to boot now

Hello there,

I want to apologize in advance because I'm not very computer-savy. I did browse the forums and guides carefully to try and get an answer for my problems, but haven't found what I need yet. I'll give you the complete story so you have as much information as possible. (BTW I'm not a native Englis-speaker.)

Two years ago a friend helped me build a hackintosh from scratch, mainly for the ability to keep using OS X (I had iMacs until then) but without throwing my money out the windows when I want to upgrade my computer (the hardware part of it; iMacs are costly). We used Multibeast and Chameleon and I had a dual boot with Snow Leopard on one hand (my prefered system), and Windows 7 on the other (for a couple games). At some point I updated Snow Leopard to Mountain Lion.

Motherboard: Gigabyte GA-Z77-D3H
CPU: Intel Core i5-3570K (3.4 Ghz)

Everything worked fine for two years, until last week. For an unknown reason my computer shut down, and at first I was not able to restart it. I thought it was the powersource or motherboard that had died. After checking everything, I was able to restart the computer, but only after resetting the BIOS. So the hardware seems fine after all; I'm still not sure what caused this (it wasn't a power outage).

Now my issue is that, with the BIOS totally reset, it can't seem to find the boot system or be able to access any of my operating systems anymore (Windows 7 and Mountain Lion). So I have a computer that can boot, to a point, and my data is intact on the hard drives, but I can't run any system. Neither would launch and I get stuck on the BIOS screen, or the further I can go is Windows 7 trying to launch (probably took over/is eclipsing OS X, now that the boot system is gone/broken). It attempts to restore itself but to no avail, so I'm stuck either way.

I'm not sure what to do and where to start:

- Is there a repairing device or some BIOS trick to restore my dual boot, from an USB key or something?

- Otherwise, do I have to re-install everything? OS X and Multibeast and Windows 7 and all?

- If I have to re-install everything, do I have to say goodbye to my hard drive partitions and data? Do I need to clear/format it all?

- If I have to re-install the Multibeast and everything, is it better to install Mountain Lion like I had and then update to Mavericks, or is it cleaner/better to install Mavericks directly? (I do not have a hard copy of Snow Leopard anymore, in any case)

Let me know if you need to know anything.

Try this:
Boot to BIOS, set optimum defaults, set the SATA port mode for AHCI, set the ML HDD as first in BBS boot order, save&exit and continue boot.

report results.

Thank you for your reply.

I followed your steps, and I feel silly about this but I'm struggling to recognize which of the HDD listed has ML on it (they only have obscure names in the BIOS, not anything like what they looked like with my Disk Utility tool on ML).

But in any case, I did what you suggested, trying each time with a different HDD from the list - reseting back the BIOS to optimized default each time, set the SATA mode to AHCI again, and set one of the HDD as first in the boot order, save and exit to boot.

Each time, it failed, telling me there was no booting device to be found.

I'm also starting to wonder if ML and Windows were on separate HDDs, or on the same HDD with distinct partitions. Is there a way for me to check which partition matchs which HDD? I have Windows 7 somewhere (180Gb disk or part), ML on a similar 180Gb disk or part, and all my data on a 1Tb disk or part. I thought they would match my 3 physical HDD and now I don't know what to think anymore.

(I know the HDDs are physically intact, because I'm able to boot a Ubuntu demo from a USB key and access all the HDDs data from there. I could make a copy of my data if, as a last resort, I need to format everything.)

Try this:
boot the UniBeast installer USB.
At the install screen select Utilities - terminal
type

diskutil list

hit enter and take a pic of the screen. Post pic if you can't figure out which which.

Alternate.
disconnect all but one drive. Boot with UniBeast USB - what icons show up at the Chimera screen?
Boot to BIOS and note what the BIOS calls the drive.
Repeat for other drives.