Download macOS High Sierra The full operating system is a free download for anyone who has purchased Mac OS X Snow Leopard, Lion, or Mountain Lion or has a Mac preloaded with OS X Mavericks, Yosemite, El Capitan, or macOS Sierra. Download the Application from the Mac App Store using your Apple ID on any Mac or functional computer running OS X 10.7.5 or later. 1. Open Mac App Store 2. Log in with your Apple ID 3. Download macOS High Sierra The Application Install macOS High Sierra will appear in /Applications. 4. Click Erase button 5. For Name: type USB (You can rename it later) 6. For Format: choose Mac OS Extended (Journaled) 7. Click Erase then Done 8. Download and run UniBeast 9. Click Continue, Continue, Continue, Continue, Agree 10. At Destination Select, choose USB and click Continue 11. At Select OS Installation screen choose High Sierra and click Continue 12. At Bootloader Options screen choose UEFI Boot Mode or Legacy Boot Mode. UEFI Boot Mode is recommended for 7/8/9/100/200 Series CustoMac desktops and all UEFI capable systems. Legacy Boot Mode is recommended for 5/6 Series CustoMac desktops and all BIOS based systems. 13. (Optional) At Graphics Configuration screen choose the appropriate graphics option for your system and click Continue. 14. Verify installation options, then click Continue, enter password and click Install UniBeast will now create the bootable USB drive. The process will only take about 10 minutes, depending on system and drive speed. Do not unplug or stop during this time. 15. Drag MultiBeast to your completed USB drive. Clover Note: UniBeast delivers basic bootloader support based on our testing on recommended CustoMac systems. For further bootloader customization, download and run the official Clover package. Advanced users may also compile Clover by downloading the full source. Gigabyte AMI UEFI BIOS, Gigabyte AWARD BIOS, ASUS AMI UEFI BIOS, and MSI AMI UEFI BIOS. 1. To access BIOS/UEFI Setup, press and hold Delete on a USB Keyboard while the system is booting up 2. Load Optimized Defaults 3. If your CPU supports VT-d, disable it 4. If your system has CFG-Lock, disable it 5. If your system has Secure Boot Mode, disable it 6. Set OS Type to Other OS 7. If your system has IO Serial Port, disable it 8. Set XHCI Handoff to Enabled 9. If you have a 6 series or x58 system with AWARD BIOS, disable USB 3.0 10. Save and exit. 4. At Clover boot screen, choose Boot OS X Install from Install macOS High Sierra 5. When you arrive at the Installer, choose language. If you have issues reaching the installer, you can use spacebar on boot screen to enter alternate boot modes such as verbose and safe mode. For more instructions on entering boot flags see Clover Basics and Switching Advice. 6. For a new installation of macOS, you MUST erase and format the destination drive according to the following steps before continuing. a. In the top menu bar choose Utilities, and open Disk Utility b. Highlight your target drive for the High Sierra installation in left column. c. Click Erase button d. For Name: type High Sierra (You can rename it later) e. For Format: choose Mac OS Extended (Journaled) f. Click Erase g. Close Disk Utility 7. When the installer asks you where to install, choose High Sierra 8. Upon completion, the system will automatically restart. 9. (Optional) Prevent APFS file system- default to HFS Some users may prefer HFS file system and want to install without converting the system disk to the new default APFS file system. To this end, we've created a script called No-Convert which is included when creating your bootable USB installer using UniBeast. Running that script in Terminal will prevent automatic APFS file system conversion. Skip this step to default to APFS. a. Press the hotkey to choose boot device (F12 for Gigabyte motherboards, F8 for ASUS motherboards, F11 for ASrock motherboards) b. Choose USB c. At Clover boot screen, choose Boot OS X Install from Install macOS High Sierra again d. After the installer completely boots, In the top menu bar choose Utilities, and open Terminal e. Type the following: Code (Text): /Volumes/Image\ Volume/No-Convert f. Reboot 10. Press the hotkey to choose boot device (F12 for Gigabyte motherboards, F8 for ASUS motherboards, F11 for ASrock motherboards) 11. Choose USB 12. At the Boot Screen, choose High Sierra 13. Complete macOS installation. The system will automatically reboot. MultiBeast 6. If this is a fresh installation, click Quick Start. UEFI Boot Mode is recommended for 7/8/9/100/200 Series CustoMac desktops and all UEFI capable systems. Legacy Boot Mode is recommended for 5/6 Series CustoMac desktops and all BIOS based systems. 7. Choose the appropriate audio and network options for your system: 8. Click Customize for further options 9. Click Print or Save to back up your configuration 10. Click Build then Install If using a GeForce GTX 1050, 1050 Ti, 1060, 1070, 1070 Ti, 1080, 1080 Ti, TITAN Pascal, and TITAN Xp 'Pascal' graphics card or NVIDIA GeForce GTX 750, 750 Ti, 950, 960, 970, 980, 980 Ti, and TITAN X 'Maxwell' graphics card, macOS High Sierra graphics drivers are not natively supported. Alternate NVIDIA drivers are required. 11. (Optional) Download and install Alternate NVIDIA Graphics Drivers 12. Reboot Yay! You now have a fully updated bootable version of macOS High Sierra on your CustoMac! And a super handy USB rescue drive. It's easy to get frustrated, but don't give up! If you get stuck, there are many users with similar hardware in the tonymacx86 Forum to provide support. Thanks to all of the hard working developers, hackers, and testers all over the world without whom this guide would never have been possible.