Install macOS on Mac Pro 4,1

I have a few ideas. The USB key has to be formatted as Master Bootable, GUID on. According to what I've seen, TransMac, on first starting of the app, will be "Read only" mode to prevent accidental file loss, and it has a 15 day trial period. Don't bother trying to access the Recovery Partition (Command+R) or trying for "Safe Mode " (command+S) because it doesn't exist. For best results, your HDD should be formatted as ExFat ?? which should be readable by both Mac and windows. You may have to use GPT, something like this (link)

https://superuser.com/questions/383235/create-a-bootable-usb-drive-from-a-dmg-file-on-windows....

might be iffy though....maybe worth a try.....

also, the CMOS battery only lasts for about 5 years..... so if you have troubles starting up, change it. a BR 2032 is the best one to use, but might be hard to find, so a CR 2032 will do. You could try plugging an Ethernet Cable into the back of the Mac Pro 4,1

and find yourself a usb keyboard and mouse, literally any usb keyboard and mouse will work, as long as they are both USB.

so, we start with the basics...reset smc/pmu: Shut down Mac Pro, remove power cord, hold down power button for about a minute, let go of button, wait about 45 seconds, plug the power cord back in and immediately do 2: zap pram... hold down on keyboard...Command, option,P and R keys together for about 3 chimes then let go, then hold down Option, command+R to get to Internet Recovery. You should be able to access OS X Tools once you get past the language selection screen by moving the mouse to the top center of the screen and then clicking, and it may appear. From there, you can run Disk Utility and format your hard drive, I'm guessing you didn't have anything on that Mac pro from before that you wanted to save, yes ? Anyways, Should be formatted as Master Bootable, not AFPS, and GUID has got to be on. when done, you could give a name of some kind, then quit disk Utility and re-install the OS, and Internet Recovery will try to get you the best fitting OS that it can for you. If you see a spinning globe on the screen and a progress bar under that , then it means you are kinda successful. Be patient and wait, and Internet recovery will do its thing......

Macs can be pretty darn picky about what they will boot up from, and the process of creating a bootable USB stick, especially from Windows, is not as cut-and-dried as you might think, as you know by now. For Mojave and the like, you'll need at least a 16 gig stick or bigger. USB stick has to be formatted for mac ahead of time, and grab a copy of El Capitan .dmg from the App store, at least that's where I got mine from, and then restore from Disk Image, and point it to the el Capitan .dmg

anyways, I tried

John B

A 4,1 Mac Pro was the first of that model line. It shipped with Leopard, 10.5.x. The newest OS it's capable of running is El Capitan, 10.11.x. So if your bootable USB stick has Sierra 10.12.x or newer on it, you will never be able to boot to that installer.

That model also has no capability for a Command+Option+R Internet Recovery startup. That has to be part of the firmware, and it didn't exist until Macs that shipped with Lion, 10.7.x or later

A Command+R startup will work, but only after you install any OS from Lion through El Capitan.

A proper bootable USB stick has the needed Utilities (like Disk Utility) on board as well as the Installer. Sometimes you had to wait after it booted, then choose Utilities off a Menu that appeared, maybe half a minute later..

Ugh ! You're probably right. Assuming it has a working dvd drive, your easiest bet would be to buy a copy of Snow Leopard (about $30) and install from that. if/when you do buy it, hold down the "C" key on startup to boot from the DVD drive

John b

A properly-prepared USB-stick is Bootable, and would show up on the boot select screen. Conversely, if it does not show up, it is not a proper bootable USB-stick.