Hi folks,
Well, decided to do something mad and installed a new 2TB drive, then use the Unibeast method of installing Mountain Lion (my main drive is running SLeopard, another drive running Lion - which I intend to delete, another drive running Windows 7 and a final SSD also running SLeopard....just to try out an SSD). Had various issues with NOT being able to boot into ML WITHOUT first booting from the unibeast USB. So......disconnected all drives EXCEPT ML, that's when I got the Boot0 error. So, connected ALL drives again, booted with USB.....found that I still had the 'installer' drive from when I successfully formatted my LION drive (as per Tonymac) and so booted into that. Then I followed the above instructions, opened Disk Utility, used 'Get Info' to find that ML drive was 'disk3' unmounted ML drive, quit DUtility, then opened Terminal and simply copied instructions per screen shots above by 'oqunnn' (THANKS!)........boots beautifully! I now have a machine (getting a bit old now) that can boot into SLeopard, Lion, Windows and now Mountain Lion!!!! (woohoo!). My aim is to transfer files from LION (which I respectfully deplored) onto ML...and just run SL (which I still LOVE and need for certain music software, not yet ML enabled) and ML. I'll also keep WIN7 (same reason as SL). Incidentally, this Hackintosh (my first ever)....has given me 2.5 years of hassle free computing (and still on the Gigabyte X58 mono).
Best wishes and thanks guys once again.
Incidentally, I needed wireless and just downloaded the ASUS wireless utility driver for 10.7 and it works wonderfully with my USB-N10.
Eco