I used to be in the same boat as you and I have a solution to your problem. I will just start from step one and guide you through. The only way for you to get Mavericks installed on this specific motherboard, it needs to be patched. You will know when the BIOS file is patched when the script in command prompt is put through and at the end it says "Output file generated."
Step 1: Download the latest version of PMPatch. The latest is 0.5.14.
http://www.insanelymac.com/forum/topic/285444-uefipatch-uefi-patching-utility/
Step 2: Download the BIOS. Get the latest version which is 1.7.
http://us.msi.com/product/mb/Z87G41_PC_Mate.html#/?div=BIOS
Step 3: Now since you have PMPatch downloaded and hopefully in your Downloads folder, you want to extract it by right clicking on the PMPatch_0.5.14_win.zip file and click on "Extract All..." A pop up will open and click on Ok and the file should unzip in the Downloads folder.
Step 4: This is the part where you are having your problem. Hopefully now you have a folder called PMPatch_0.5.14_win. Open the folder and rename the .exe file to "PMPatch.exe".
Step 5: Now take the BIOS file which should be named "E7850IMS.170" and copy it to the PMPatch_0.5.14_win folder.
Step 6: Now here is the script. It should look something like this: "PMPatch input.file output.file"
If you are using BIOS version 1.7, then what you want to do is path your way to the PMPatch folder. Once in the PMPatch folder type in this: PMPatch E7850IMS.170 pE7850IMS.170
Step 7: Now there should be a new file called "pE7850IMS.170". This is the new patched file. Now we shall proceed to updating the BIOS by creating the USB.
Step 8: Plug in a USB to your computer and format it. To format, right click on the USB and click "Format". Now make sure that the file system is set to FAT32. Also tick "Quick Format" since it isn't required to do a full format. Once the USB is formatted, copy the new patched bios file to the root of the USB. Root meaning not in any folder, just directly onto the USB. Also rename the patched bios file to just "E7850IMS.170" so the BIOS is able to recognize it better.
Step 9: Turn off the computer, plug in the USB you just created and boot into the BIOS. On the left side of your screen, click on "M-Flash"
Step 10: Click on "Update BIOS"
Step 11: Since the BIOS we are flashing is fairly new, MSI requires us to update the BIOS using the option "BIOS + ME." So choose the option that says "Select one file to update BIOS and ME"
Step 12: Then it will tell you to choose your USB, and then select the file. Let the computer do its thing. It will restart once or twice so don't be alarmed. After the process, your BIOS should be patched!
Even after it is patched, you will most likely run into problems. Just like I did and spent countless hours on trying to fix it and finally got a fully running Mavericks install just yesterday night. Here are a few tips:
- When installing Mavericks, only have ONE STICK OF RAM installed on the computer throughout the whole process. If you do not do this, you will for sure get a kernel panic. I have learned this the hard way. For example, if you have 2 x 4GB RAM installed on your computer like I did, take out one stick and leave only one 4GB stick installed. After post-installation process, you can re-install the other stick of RAM.
- Also in your BIOS, under OC (Overclocking setting), scroll down to "CPU Features", and Disable VT-d Tech. If you do not do this, you will run into problems. Even if you have another windows partition or a separate drive for just Windows, just like me, it will not affect it because it practically does nothing.
- Now you should be able to install Mavericks following the tonymacx86 guide: http://www.tonymacx86.com/374-unibeast-install-os-x-mavericks-any-supported-intel-based-pc.html
There should be no need to use boot arguments.
- Once you have been able to successfully instal Mavericks and you are at the part where you have to use Multibeast. Use whatever drivers and stuff that you need to proceed. Also when you first open Multibeast, choose the "DSDT Free" option. Also untick the "3rd Party SATA" option that is pre selected under "Disk". This has caused me kernel panics and isn't necessary. This is what my configurations look like at the end:
After all those steps, you should have a fully functional Mavericks install.
I hope this helped you and answered your problem! If you have any questions, please feel free to ask me. Now I must go on my scavenge to find out why Mavericks freezes whenever I use Safari or Chrome.
P.S.: Sorry for the slanted pictures, I used my iPhone and didn't realize that this was going to happen.