Upgrade mountain lion to sierra

[cm1]

1. 1st hurdle seems to be that I cannot download sierra presumably because my machine is masquerading as an IMac 13.1. My install uses chimera boot loader and I have not seen instructions on how to change to say 14.2. Please provide a link on how to do this.
2. Are there any issues I need to be aware of in doing this upgrade when I can finally download sierra, e.g. is there any need to change boot loader to clover which most people seem to be using nowadays.

Hope someone can help. None of the info I have seen seems to cover this.

Thanks in advance.

 

[P1LGRIM]

1. 1st hurdle seems to be that I cannot download sierra presumably because my machine is masquerading as an IMac 13.1. My install uses chimera boot loader and I have not seen instructions on how to change to say 14.2. Please provide a link on how to do this.
2. Are there any issues I need to be aware of in doing this upgrade when I can finally download sierra, e.g. is there any need to change boot loader to clover which most people seem to be using nowadays.

Hope someone can help. None of the info I have seen seems to cover this.

Thanks in advance.

iMac 13.1 is not the problem - It qualifies for the upgrade to Sierra.

 

[cmn699]

1. 1st hurdle seems to be that I cannot download sierra presumably because my machine is masquerading as an IMac 13.1. My install uses chimera boot loader and I have not seen instructions on how to change to say 14.2. Please provide a link on how to do this.
2. Are there any issues I need to be aware of in doing this upgrade when I can finally download sierra, e.g. is there any need to change boot loader to clover which most people seem to be using nowadays.

Hope someone can help. None of the info I have seen seems to cover this.

Thanks in advance.

Is your system SPECS the same as the one in your Profile? What video card are you planning to use?

I have GA-Z77X-UP5Th Socket 1155 that supports Sierra up to the 10.12.3. But I use an add on Video card. Is your CPU i5 3570 K? If it is 3570 K it must be SSE4.2 and should support Intel HD 4000 I guess.

My guess is your system can install Sierra. In my system I have installed System Definition 14.2

Since you have Mountain Lion on Chimera and in Sierra [most of us who follow Tonymac Guide] we use CLOVER as the boot loader.
My suggestion will be to set aside the current ML system disk and use a blank SATA HDD or SSD to install Sierra. You may be able to download the macOSSierra 10.12 Installer file in your current system. But don't Install it Right away to the Disk. Instead Create a Sierra Installer Disk using a Flash Disk formatted through Disk Utility in GUID partition Map and MacOS Extended (Journaled) format scheme and follow all the steps in the Tonymac Sierra Guide. I suggest creating in UEFI mode ( MoBO has UEFI) not in Legacy as the board can support that.
Hope this helps to start your project.

 

[cm1]

Is your system SPECS the same as the one in your Profile? What video card are you planning to use?

I have GA-Z77X-UP5Th Socket 1155 that supports Sierra up to the 10.12.3. But I use an add on Video card. Is your CPU i5 3570 K? If it is 3570 K it must be SSE4.2 and should support Intel HD 4000 I guess.

My guess is your system can install Sierra. In my system I have installed System Definition 14.2

Since you have Mountain Lion on Chimera and in Sierra [most of us who follow Tonymac Guide] we use CLOVER as the boot loader.
My suggestion will be to set aside the current ML system disk and use a blank SATA HDD or SSD to install Sierra. You may be able to download the macOSSierra 10.12 Installer file in your current system. But don't Install it Right away to the Disk. Instead Create a Sierra Installer Disk using a Flash Disk formatted through Disk Utility in GUID partition Map and MacOS Extended (Journaled) format scheme and follow all the steps in the Tonymac Sierra Guide. I suggest creating in UEFI mode ( MoBO has UEFI) not in Legacy as the board can support that.
Hope this helps to start your project.

Thanks for the info. Yes the system is the same as the profile. I don't have a separate video card but use the on chip one. I am fairly sure sierra will run but the problem is I cannot download it as presumably my system spec is not correct which brings me back to point one - how to configure it so it meets apple's criteria for downloading. I have seen words on configuring clover config.plist files but I don't have any of those. Once I get hold of Sierra then I am sure I can just follow the guides.

 

[cmn699]

I don't know how exactly (detailed steps) you had tried to download macOS Sierra Installer to your current system and encountered the problem. But, try to click this link I am pasting and start clicking the MacOSSierra icon that shows up to get to Apple store to get the download link:
https://itunes.apple.com/us/app/macos-sierra/id1127487414?mt=12
Edited to add one more line:
Another option is to try to download el Capitan installer. Install it using Clover UEFI mode and then download macOS Sierra

 

[cm1]

I simply went to the apple store and clicked on the link to download sierra and then I get a message saying I cannot download as it is not supported hardware - so unfortunately the link above does not help - I can access the sierra link but it just fails for the reasons stated (I don't have the exact wording to hand as this is being written on Windows). So to proceed I need to either (i) Be able to download an update from ML to Sierra on another machine/os (ii) Fix the machine spec that is being reported on the ml mac so that the apple store will allow the download (note their is nothing clear in the message that says what the problem is - just that the spec is not correct). I would imagine someone has had this problem before. I have seen posts on the same subject but the suggestions all seem to have clover specific steps and my system uses chimera.