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clarkr

macrumors newbie
Original poster
Sep 30, 2025
11
1
Hi all and thanks in advance, it's been a while.

Have a 21.5" mid 2011 imac. New Two Terabyte HD, 12 GB ram. AMD Radeon HD 6770M 512 MB graphics card. I am currently running OS Sierra 10.12.6.

Problem 1: My old hard drive crashed so bought a new one. Installed El Capitan on it and upgraded it to Sierra. Mac side boots and runs OK.

Now trying to install Windows 8.1 on a Bootcamp partition without ANY luck. The reason I need 8.1 on my system is so I can run an older version of Photoshop I purchased in the past. (Please don't suggest upgrading to Adobe's rent-a-software. I am a retired Commercial Artist that only uses it occasionally for personal use.) At the moment I am using my son's PC to get online.

Problem 2: My internal optical drive on my imac will not mount the windows install disk. It ejects it every time. The optical works on any DVD but the Windows disk so I don't see how this is a problem but it is. I have the original Windows 8.1 legitimate installation disk with key. Also tried an old ISO Windows install disk. This didn't register when boot/option.

Problem 3: Using Bootcamp 6.1.0 I selected both check boxes. The Download latest Windows support file downloads the files but won't install them because it's for Windows 10. Unchecked box and ran with Remove Windows 7 or 8.

I created Bootcamp partition formatted in Dos Fat32 with MBR. Put my windows disk into an external drive and after reboot selected EFI boot which loaded the Windows disk in external drive. Went through the whole process of key etc. and got to where to install. Error says couldn't install EFI on Bootcamp partition, needs to install on GPT disk. Windows must be installed on NTFS partition.

Tried to create a USB boot drive. Never showed up on boot with option held down.

OK, reformatted drive in BC to GUID format. Didn't work because I read that the mac changes the formatting to two separate types of format, a hybrid, that won't install this software. Tried WinDiskWriter still no joy. Used fdisk to remove security coding and installed NTFS. Got the software to install from EFI boot to Bootcamp partition. Then converted the drives back to having the sercurity setting with fdisk.

Was booted in Windows 8.1. Installed new software and virus software. Transfered about a hundred GB's of back up files over. Booted fine until I went into the mac side. Tried to boot into Windows. Wouldn't boot. Only EFE boot disk to boot into Windows. All my 2 days of work was gone. No options to boot into Windows Bootcamp.

These are just a few of the things I have tried to get Windows to install. The black screen, the flashing cursor in upper left corner, the blue screen of death from windows. I have tried so many things I really can't even remember where I am at with it. I have literally been working on this for over 60 hours and no joy.

Can anyone PLEASE help me get this to work?

Thanks,

Clark
 
Recognizing that this isn't particularly intuitive... updating the iMac to the latest supported version of OS X (and of Bootcamp) is likely where you went astray. Since you're attempting to install an older version of Windows, you would have probably had a better chance of success if you had installed a version of macOS which is of a similar vintage to that version of Windows -- in this case, I believe that would be 10.9 (Mavericks). Unfortunately, Apple isn't historically very friendly to downgrading, so that may or may not be an option at this point; specifically, sometimes firmware updates to support the newer OS limit your downgrade options.

Still, if you don't have anything important on that installation yet, it might be worth a try. If the iMac will let you install Mavericks on it, then you can use the version of BootCamp that came with that to install Windows 8. Once that's done, you should be able to upgrade OS X back to the latest supported version.
 
Recognizing that this isn't particularly intuitive... updating the iMac to the latest supported version of OS X (and of Bootcamp) is likely where you went astray. Since you're attempting to install an older version of Windows, you would have probably had a better chance of success if you had installed a version of macOS which is of a similar vintage to that version of Windows -- in this case, I believe that would be 10.9 (Mavericks). Unfortunately, Apple isn't historically very friendly to downgrading, so that may or may not be an option at this point; specifically, sometimes firmware updates to support the newer OS limit your downgrade options.

Still, if you don't have anything important on that installation yet, it might be worth a try. If the iMac will let you install Mavericks on it, then you can use the version of BootCamp that came with that to install Windows 8. Once that's done, you should be able to upgrade OS X back to the latest supported version.
Thanks zarmanto. Ok where would I find Mavericks to download. I have a ton of time put into the Bootcamp portion on updating system software and app, virus, software plus backup files (90 Gigs) but if this will cure the mess Apple has created for me I am willing to try it.

As it stands now in the Apple choose disk startup there is a listing for Windows 8.1 but it won't boot into that. I can boot into windows using EFI boot when holding option key. Have no idea what that is or if it's taking up a double of disk space.

Thanks, Clark
 
Recognizing that this isn't particularly intuitive... updating the iMac to the latest supported version of OS X (and of Bootcamp) is likely where you went astray. Since you're attempting to install an older version of Windows, you would have probably had a better chance of success if you had installed a version of macOS which is of a similar vintage to that version of Windows -- in this case, I believe that would be 10.9 (Mavericks). Unfortunately, Apple isn't historically very friendly to downgrading, so that may or may not be an option at this point; specifically, sometimes firmware updates to support the newer OS limit your downgrade options.

Still, if you don't have anything important on that installation yet, it might be worth a try. If the iMac will let you install Mavericks on it, then you can use the version of BootCamp that came with that to install Windows 8. Once that's done, you should be able to upgrade OS X back to the latest supported version.
OK, I found a Mavericks ISO download on the Internet Archive Site and am downloading it to a flash/thumb drive. How do I reformat my imac to install it? I am sure it will say it can't install an older version so it will need a wipe. How do I do that?

I formatted the flash drive to an NTFS format. Is that ok?

Thanks again, Clark
 
OK, I found a Mavericks ISO download on the Internet Archive Site and am downloading it to a flash/thumb drive. How do I reformat my imac to install it? I am sure it will say it can't install an older version so it will need a wipe. How do I do that?

I formatted the flash drive to an NTFS format. Is that ok?

Thanks again, Clark
Microsoft's NTFS isn't bootable for an OS X install image; you need to use an Apple partition scheme. But that's not overly concerning, since the imaging process should reformat the destination volume with the correct partition scheme.

Normally, I'd urge you to only use "official channels" for your install image -- but in an odd twist of fate, Mavericks happens to be the one OS missing from Apple's support documents. All versions down to 10.10 are listed... and then it skips down to 10.8. Very weird.

It's been awhile since I've tried creating a bootable USB for Mac, but I think you may be able to just use Disk Utility on any running Mac to image your ISO to a USB stick. After imaging, it should theoretically be bootable with no additional steps -- but sometimes this fails.

Another possible alternative is, you can attempt to come up with your own variant imaging command for Apple's command line utility, based upon Apple's official "Create a bootable installer" support document. That doc does not provide the exact command for OSes older than 10.11, but it doesn't look terribly difficult to decode. For this scenario, you would need to mount the ISO on the desktop of your Mac, find the installer package on the volume, and verify that it contains the "createinstallmedia" resource within that package. That said: even in the best of circumstances, this can also fail on rare occasions.

Worst case scenario is, you may have to use the ISO for it's original intended purpose, and create a bootable DVD instead. Note that the Mavericks install image is over 5GB, so you'll need to use a dual-layer (8GB) DVD to successfully image it.
 
Last edited:
Microsoft's NTFS isn't bootable for an OS X install image; you need to use an Apple partition scheme. But that's not overly concerning, since the imaging process should reformat the destination volume with the correct partition scheme.

Normally, I'd urge you to only use "official channels" for your install image -- but in an odd twist of fate, Mavericks happens to be the one OS missing from Apple's support documents. All versions down to 10.10 are listed... and then it skips down to 10.8. Very weird.

It's been awhile since I've tried creating a bootable USB for Mac, but I think you may be able to just use Disk Utility on any running Mac to image your ISO to a USB stick. After imaging, it should theoretically be bootable with no additional steps -- but sometimes this fails.

Another possible alternative is, you can attempt to come up with your own variant imaging command for Apple's command line utility, based upon Apple's official "Create a bootable installer" support document. That doc does not provide the exact command for OSes older than 10.11, but it doesn't look terribly difficult to decode. For this scenario, you would need to mount the ISO on the desktop of your Mac, find the installer package on the volume, and verify that it contains the "createinstallmedia" resource within that package. That said: even in the best of circumstances, this can also fail on rare occasions.

Worst case scenario is, you may have to use the ISO for it's original intended purpose, and create a bootable DVD instead. Note that the Mavericks install image is over 5GB, so you'll need to use a dual-layer (8GB) DVD to successfully image it.
OK, seems like I am back at square one again.

After 3 days finally got a USB Mavericks installer to work. Wiped the hard drive. Installed the software with no hitches. Now on to Bootcamp...

Same items. Can't mount Windows 8.1 Install DVD into imac internal optical bay. Keeps ejecting it.

It will load in an external DVD drive. I can run bootcamp with this installed while booted into Mavericks. When it restarts to install Windows I get a blinking bar upper left corner of black screen.

When I boot up with option key to list it reads left to right... Mac OS, Recovery 10-.9.5, Windows (DVD icon), EFI Boot (DVD Icon).

1. If I click the Windows DVD I get a reboot with an empty black screen that will sit there til the cows come home.

2. If I click on the Windows EFI disk icon: Press any key to boot into CD or DVD. Click a key and windows starts to load. Click on Install Now. Asks for key which I type in. Goes to Accept License Terms and click OK. Select Custom Install Windows only (advanced). This brings up Where do you want to install Windows menu.

Four partitions listed...
Name - Drive 0 Partition 1, Total Size 200 MB, - Free Space 0.0 MB, - Type: Primary
Name - Drive 0 Partition 2, Total Size 327.4 GB, - Free Space 0.0 MB, - Type: Primary
Name - Drive 0 Partition 3, Total Size 619.0 MB, - Free Space 0.0 MB, - Type: Primary
Name - Drive 0 Partition 4: BOOTCAMP, Total Size 1534.8 GB, - Free Space 1534.4 GB, - Type: Primary

(I am assuming that partition 2 is the Mac partition. Have no clue what #1 or #3 are.)

All partitions have error message: Windows can't be installed on drives (show details)

When clicking on that "show details link" a window pops up and says:

"Windows can't be installed to this disk. The slelected disk has an MBR partition table. On EFI system, Windows can only be installed to GPT disks.

Windows cannot be installed to this hard disk space. Windows must be installed to a partition formatted as NTFS."

There are options to click on in the lower part of this window. Refresh, Delete, Format, Load driver (Extend and New have no link). I have not clicked on any of these yet.

I am exactly where I was three days ago before working on installing Mavericks. I thought this was supposed to be a fix for this? Now what? Do I have to find Mountain Lion and install it?

Thanks,
Clark
 
Have you tried a Win7 or Win10 image?
I don't have a Windows 7 full version just an upgrade when I went on up the ladder from XP. I can't use Windows 10. It will not run my older version of Photoshop on it, thus the 8.1.

On that note, I formatted a flash drive to do an ISO of Windows. There is a difference on this Mavericks downgrade from Sierra. It is actually installing the Windows Support Files in Bootcamp Assistant.

Have my fingers crossed this will solve the Windows load onto USB for boot disk
 
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Four partitions listed...
Name - Drive 0 Partition 1, Total Size 200 MB, - Free Space 0.0 MB, - Type: Primary
Name - Drive 0 Partition 2, Total Size 327.4 GB, - Free Space 0.0 MB, - Type: Primary
Name - Drive 0 Partition 3, Total Size 619.0 MB, - Free Space 0.0 MB, - Type: Primary
Name - Drive 0 Partition 4: BOOTCAMP, Total Size 1534.8 GB, - Free Space 1534.4 GB, - Type: Primary

(I am assuming that partition 2 is the Mac partition. Have no clue what #1 or #3 are.)

Supposedly, partitions 1 and 3 are some kind of padding that's created during the bootcamp process, having to do with "EFI alignment on SSDs" or some such. AI search results suggest that you can delete them -- but recommends that you only do so from Disk Utility -- not from the Windows installer. Personally, I'd suggest that you leave them alone, as I don't particularly trust the AI to be entirely right about that detail.

... Windows cannot be installed to this hard disk space. Windows must be installed to a partition formatted as NTFS."

There are options to click on in the lower part of this window. Refresh, Delete, Format, Load driver (Extend and New have no link). I have not clicked on any of these yet. ...

Yeah... Microsoft errors aren't always helpful; they'll tell you what's wrong, but not what you can do about it. And when they do tell you what you can do about it... that's usually either too cryptic for non-techies or simply outright incorrect.

Delete the bootcamp partition 4. That should change the list of partitions to include free disk space in its place; you should be able to select that free space and install, whereupon Windows will create the partition that it needs. (Reference: personal experience)
 
Supposedly, partitions 1 and 3 are some kind of padding that's created during the bootcamp process, having to do with "EFI alignment on SSDs" or some such. AI search results suggest that you can delete them -- but recommends that you only do so from Disk Utility -- not from the Windows installer. Personally, I'd suggest that you leave them alone, as I don't particularly trust the AI to be entirely right about that detail.



Yeah... Microsoft errors aren't always helpful; they'll tell you what's wrong, but not what you can do about it. And when they do tell you what you can do about it... that's usually either too cryptic for non-techies or simply outright incorrect.

Delete the bootcamp partition 4. That should change the list of partitions to include free disk space in its place; you should be able to select that free space and install, whereupon Windows will create the partition that it needs. (Reference: personal experience)
thanks for the help guys I appreciate it. As of right now I am back to where I started from 10 days and about 60 actual hours ago. This process should be an easy install no longer than a half hour. Great job by Apple's grade school programmers.

I have run so many options and scenario's I don't even know where I am at now.

Still with the same problems with the internal optical drive. It ejects anything to do with Windows. It will mount software DVD'd and such but not those. Have spent hours looking for a solution without finding one.

The software boots on an external DVD drive. But when I option boot and the DVD is listed along with EFI boot DVD and click on Windows disk it either goes to a black screen with flashing line on upper left corner (it did this when I first started) or if I can get it to boot from the dvd it sometimes will go to a blank black screen and won't load anything.

Last Two Tries - ALL Day Long:

1. Tried making a boot disk from an ISO disk I have. I can copy the file to the desktop and it creates a volume. I don't know what to do with it after that. Bootcamp won't recognize it to make a USB install. I can't copy it to a USB because I get an error: privacy.rtf won't copy because same named file on destination volume (which is formatted blank). There is no way to change or delete the files name as it is locked. I searched to find the file with the same name. No file exists I can find.

The only option I can do with the mounted volume is burn it to disk. I get a write error from the internal drive. So now I have wasted mega hours downloading and trying to find work arounds on ISO installation.

2. I downloaded the files to a USB in bootcamp that are supposed to contain drivers and such (at least that much has worked). I booted my Windows disk up and partitioned the drive. It auto rebooted after this (I think) and went to the blinking screen. Rebooted with option and USB didn't show up, just the DVD Windows. Clicked on that and booted into blank screen or blinking bar (can't remember any more).

No luck booting from the installer disk. Clicked on the EFI boot icon. Boots into Windows. Install key for the thousandth time. Got to the screen with list of drives. All have error that EFI needs GUID? type of formatting. Mine appears to be MBR or some other thing I don't remember. Tried erasing bootcamp drive in this section. Still no luck.

Quite frankly I am to the point of taking this piece of Apple garbage outside and beating it into rubble with a sledge hammer.

Besides doing that, does anyone have any ideas?

Thanks again in advance,
Clark
 
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