Booting macOS from an external hard drive?

Is this even possible?

Basically, my macOS is acting up. I've got macOS on a USB drive, but it just won't boot. Is there any way I can boot directly from the hard drive instead?

Thanks.

Are you thinking about taking a hard drive from another PC running macOS and just plugging it into your own rig to boot it up? Honestly, you’ll most likely run straight into a Blue Screen of Death... Since the hardware components will be different—and they almost certainly are if it's from a different machine—macOS remembers specific chipsets, drivers, and all those little technical details. Most of the time, it isn't nearly that simple to just swap drives and expect things to work perfectly.

I've got three hard drives in my rig, so I was thinking about ditching macOS and installing it on one drive, then just booting from a different one.

But why not just burn the ISO file onto a blank DVD—or better yet, use a tool like Rufus to make a bootable USB drive? Then you could just install macOS on that other computer. Seems like a much smoother way to go, if you ask me.

I don't have a CD drive. I just picked up a new motherboard that uses SATA, but my old drive is outdated. Now I'm looking at having to shell out $43 for a new one, and honestly, my budget is tight right now. So, I wanted to see if there's any way to boot directly from a hard drive instead. I'm running Windows 7.

To be honest, I’ve never actually tried it myself. I have heard stories from people who ran into major headaches after switching up their entire setup—you know, swapping out an AMD processor for an Intel one. Apparently, once they made the jump to an Intel CPU and a new motherboard, they couldn't get Windows to boot at all. They ended up having to do a completely fresh installation because the chipsets and drivers just wouldn't play nice together, leading to a constant Blue Screen of Death every time they tried to start up. So, I'm not entirely sure, but I guess you don't really have anything to lose by giving it a shot? Since you mentioned you don't have an optical drive, a USB stick should work just fine. You can easily put together a bootable drive using a tool like Rufus.

I tried using USB yesterday twice, but it keeps telling me the device isn't recognized. I even swapped to different USB ports, but no luck—same exact thing.

Well, in that case, give this solution a shot. Basically, once you finish installing Windows, don't go ahead and install any drivers or anything else right away. As soon as the installation wraps up, just shut down the PC and unplug the hard drive.

Chris Robinson25 said:I tried doing this via USB twice yesterday, and it keeps telling me the device isn't recognized. Swapped out the ports, tried different ones—same exact result.

Where exactly is it saying the USB drive isn't recognized? Your motherboard should be seeing it and giving you the option to boot from it; honestly, every board made in the last decade can handle that. If you're getting that error inside Rufus, try using this.

Motherboards also come equipped with one ATA slot.

rowdybadger18 said:Where exactly does it say it isn't recognizing the USB drive? Your motherboard should definitely see it and give you the option to boot from it—pretty much every board made in the last ten years can do that. If you're getting an error message inside Rufus, try using this instead.

The Windows installation starts up fine, but once I hit that menu where you pick your partitions, it tells me there's no USB plugged in. It works perfectly fine for the initial boot, though.

Look, you aren't supposed to be selecting a USB drive here; you need to pick your actual hard drive.🤷

Here’s the issue

http://oi59.tinypic.com/140w1tv.jpg

E: forgot the img code, now the picture is huge.

Head straight into the BIOS. You'll need to disable SATA Native Control and switch the setting to Compatibility, or if your menu allows, just toggle from AHCI over to ATA.

While you're in there, make sure you set USB Legacy to Enable.

I'm gonna give this a shot and let you know how it goes.

Edit: I don't see an ATA option in here. It just shows AHCI and some IDE setting. No ATA.

So, back to square one. Looks like I'm getting totally screwed over here. Guess I'll just have to go grab a soldering iron after all.

Just switch over the IDE then. And regarding the pork, you’re already up to speed on all that... see you tomorrow 😁

Noah Miller6 said:Go ahead and switch over to IDE then. As for the fried fish, you're already an expert... see you tomorrow 😁

Seriously, thanks. 🙂 You really saved my skin here.

In case this helps someone else out: I tried adding a second hard drive to my Lenovo using the DVD bay instead of the disc drive, and it completely prevented Windows 7 from booting up.

I eventually figured out the fix. When you first turn the laptop on, tap F1 to get into the BIOS. Look for the disk options and switch the AHCI setting to COMPATIBILITY mode. Once I did that, Windows recognized the extra drive without any issues. ☕