Installation of OS X 10.8.2 Mountain Lion on PC based computer

This tutorial shows how to install Retail Mac OS X Mountain Lion 10.8.2 64 bit on a PC based computer. It’s made specific for the Gigabyte GA EP41-UD3L main board, but most of tutorial should work for most intel based main boards and core2duo or later processors. You just need to know exact hardware you use, and than select specific drivers and (if u use) DSDT.aml for your main board. Mountain Lion does not support 32 bit mode anymore…

MOBO: Gigabyte GA EP41-UD3L rev 1.2 Bios F5 (Intel G41, ICH7 chipset), integrated Lan: RTL8111C/D(L), integrated Audio: Realtek ALC888
Graphics card: Sapphire ATI Radeon HD 6670 (check osx86 project for compatible graphic cards)
CPU: intel q9550 core2quad processor,
SATA SSD OCZ Vertex 4 vtx-25sat3-128G,
SATA DVD Sony Optiarc, 2x2GB of Kingston KVR800D2K2 memory, Logitech USB Mouse, Logitech USB Keyboard.

You will need USB drive (8 GB or larger): USB drive used for Unibeast (Mountain Lion) must be at least 8 GB in size. Make sure to back up its contents first, cause unibeast will erase all of the files on your USB drive. You can reuse it after you finish installing Mountain Lion (just format it back to your desired file system).

This tutorial is for educational purposes only. You, of course, assume all responsibility for choosing to follow this tutorial. Also, OS X EULA states that you can run Lion on Apple labeled hardware only.

Required files:
– Mountain Lion 10.8.2 from app store, or search torrents if u wanna test if your system is capable to run OS X 10.8.2. Anyway OS X Mountain Lion costs only 20$, buy it.
– UniBeast and Multibeast for Mountain Lion from
– ShowAllFiles app (to show hidden files) download from
– for GA EP41-UD3L bios F5 main board you can use this DSDT.aml file
– Kext Utility – download from here

First step is to create bootable USB disk.

To create bootable USB drive I used Unibeast method, whole process is described in this tutorial.
Otherwise there are alternative bootloader installers as myHack or Kakewalk. For myHack method  you can follow this tutorial.

Time to move over to second step, setting up the BIOS and installing system.

At this point you’ll need to plug your bootable USB drive into your computer and enter the BIOS. This step is going to be different depending on what motherboard you have but it’s fairly straightforward. First find boot options and select USB hard drive as your first boot device. Then double check that your motherboard is set to AHCI mode. Save the changes and it should boot from your UniBeast drive.

On GA EP41-UD3L main board, there is no AHCI settings (ich7 chipset don’t support AHCI), so  you are not going to be able to enable Trim Support for any SSD drive. Anyway it’s possible to install ML without AHCI.
Turn on your computer, press delete to load bios, choose “LOAD OPTIMIZED DEFAULTS” and than change your settings like on pics bellow (not all changes are essentiall, but it’s the way I prefer).


At the end save BIOS (F10) and try to boot your PC with UniBeast USB drive. When UniBeast starts, select USB and press enter. If you have issues try again but this time type GraphicsEnabler=No in the prompt. If you’re still having problems try booting with the -v flag and noting what error you get.

If using ATI HD 6670 graphics, and if you get a “white screen with a cursor error” on the installation it is due to a bug on “ATI6000Controller.kext” drivers on the installer, you have to remove the /System/Library/Extensions/ATI6000Controller.kext  from the install media and boot it ignoring caches and disabling Graphics Enabler ( -f  GraphicsEnabler=No ). Remember to make a copy of “ATI6000Controller.kext” before u delete it, you’ll need it later.

Once it boots you should see the OS X installer. We’re most of the way there however there’s one more thing to do before installing. Come up to the top menu and select Disk Utility. Here you should see all hard drives connecting to your computer. Pick the one you want to install Mountain Lion on and select the Partition tab. In options select GUID Partition Table then choose Mac OS Extended Journaled as the format and name it HDD. Then click Apply.

Close Disk Utility and go through the installer like normal. When it comes to the install screen just pick the Mountain Lion disk and then click install. This will take quite a while so be patient and let it do its thing. Reboot after installation finish.

GA EP41-UD3L Bios will probably reset, just select Last Good Configuration and you are good to continue…
Reboot back into the UniBeast USB drive.
This time select HDD to boot from, and then continue installation.

Third step: creating bootable OS X 10.8.2 system

First go to System Preferences / Security and Privacy and unlock the preferences. Under “Allow applications downloaded from” select “Anywhere” and close preferences.

Head over to the downloads section on and download MultiBeast for Mountain Lion. Again go through the installer until you reach the options. Here you need to choose EasyBeast or UserDSDT with a prebuilt DSDT file.

For GA EP41-UD3L bios F5  I used this DSDT.aml file, you need to unzip and put DSDT.aml on your desktop and than start MultiBeast.

If you need/want to create your own DSDT.aml first download DSDT editor from, unzip it and than open. System will automatically ask to instal Java, so just accept it and wait DSDT Editor to open. Download GA EP41-UD3L – HD6670 extra pack (unzip it)

Under DSDT Editor select File / Extract DSDT.

Than select Patch and press Open, select GA-EP41-UD3L-patch.txt from GA EP41-UD3L – HD6670 extra pack and press Apply. Close Patch and open it again, but now select GA-EP41-UD3L-APPLE-HDA-patch.txt, Apply and close Patch again. Now press IASL and select compile, Press Fix errors and close Compile.  again press IASL and now select Save AML as and save it as DSDT.aml to your desktop.

For more detailed explanation on how to extract and compile DSDT.aml with DSDT Editor follow this tutorial.

Now, continue with MultiBeast, under options you choose UserDSDT or DSDT-Free Installation.

Next click arrows to open Drivers and Bootloaders / Drivers / Audio / Realtek ALC8xx / With DSDT / ALC888 and than select v100202 Legacy.
Under Network select Lnx2Mac’s RealtekRTL81xx Ethernet v0.0.90, and finally  under Bootloaders check Chimera v1.11.1 r1394. Continue and finish the installation.

Reboot your computer and now you should be able to boot from your HDD without USB.

Depending on your Graphics card, now its time to install your graphics.
for ATI HD 6670 Graphics you will need to boot with GraphicsEnabler=No option every time until you do this steps:
copy “ATI6000Controller.kext” you removed from USB installation media into the /System/Library/Extensions/ on your HDD. Open /Extra/org.chameleon.Boot.plist and add this line:


Run Kext Utility to fix file permissions.

Reboot your computer and you are good to go, everything should be fully operational, so now you can enjoy your new OS X Mountain Lion 🙂 !

8 thoughts on “Installation of OS X 10.8.2 Mountain Lion on PC based computer

  1. Thank you so much for writing up the guide. Your dsdt.aml file didn’t work for me, keeps crashing, so I switched to Multibeast Easy Dsdt.aml works like a charm. And oh, I have an Nvidia gt430 card. Couldn’t change resolution, got stuck on blue screen. Downloaded new Nvidia drivers for OSX, and poof, all now is working.
    Great guide. Thanks man..

    1. ty, I’m glad this helps someone….
      can u tell us, did u install any other kext for gt430 card, or just nvidia driver?

  2. Would anyone tell me, does installing osx on my system would harm ma windows or i will get os selection menu? This is my development machine and i don’t want to crash my system? Please do reply soon.

    1. Yes, it can harm your windows, however dual boot is possible, but i suggest you to use another HDD to test and install OsX.

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