Can Sierra be installed on a virtual machine created by Parallels Desktop 10? I’ve just stumbled across this site by accident and you good folk may be my last good hope before I abandon this endeavour. 

My questions are simple: 


Can Sierra be installed on a virtual
machine created by Parallels Desktop 10? 
If 'yes' to 1, how do I do this?


—BACKGROUND—

I’ve heard a lot of conflicting stories about Sierra and would like to test it before taking the plunge of upgrading. I have a 27 inch mid 2011 iMac maxed out with 32GB RAM. I regularly run virtual machines in Parallels Desktop 10. These VMs (Windows XP, Windows 7, and Windows 8.1) all work splendidly, so I figure I could try running Sierra on a virtual machine too.

I’ve read Apple’s licensing conditions and this is legal. Since my iMac is capable of running Sierra natively, my conclusion is my hardware will run Sierra fine in a virtual machine too.

Now the problem…I can’t seem to create a Sierra virtual machine in Parallels Desktop 10. 

I’ve tried following and adapting the steps found at this discussion forum (https://forums.developer.apple.com/message/143196), but with no joy to be found. Only frustration!

I’ve searched online (including here!) and cannot find confirmation anywhere that I can even do this on Parallels 10. Nothing to say it can be done. Nothing to say it cannot be done.

Apparently I have to purchase Parallels Desktop 12, or get my hands on Parallels Desktop 11 (cheaper) and create an El Capitan virtual machine and then upgrade to Sierra from within the VM (see http://blog.parallels.com/2016/06/16/macos-sierra-vm/). Thing is, I have no reason to upgrade from Parelles Desktop 10 as it meets my needs otherwise. Besides, Apple doesn’t charge for Sierra so why should I spend money to install it on a virtual machine? 

In principle I believe this should be possible somehow and I’m frustrated within myself that I can’t seem to do it!
Yes, this is possible. 

It’s not actually too hard, but there’s a lot of steps (a couple of which can be fiddly) so be patient and read this carefully. I’ll try and outline all the steps involved, but feel free to let me know if you get stuck at all. 

Also, some of these steps are not strictly necessary, but I’m trying to make this foolproof so that it's useful to other users, and also because I want to ensure that my Terminal command at Step 12 can just be copied and pasted.


On your iMac, download the macOS Sierra installer via the Mac App Store
After its downloaded, the installer will launch automatically. When it does, quit the installer.
Grab a USB flash drive of at least 8GB in size
Connect the USB flash drive to your Mac
Launch the Disk Utility app (by default it’s in the Applications > Utilities folder)
Select the USB flash drive on the lefthand side
Click on the Erase tab
Do not change the default name of Untitled
Click on the Erase button (do not worry about any of the other settings). Note this will totally erase your drive!
Quit Disk Utility
Launch the Terminal app (by default it’s in the Applications > Utilities folder)
Now enter the following command into Terminal. It may be best to just copy it from here (try triple-clicking) and paste it in. 

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ macOS\ Sierra.app
You will be prompted to enter your user password. Enter it now and press return (note that you won’t see the cursor move or display any of the characters you enter)
At the next prompt (about erasing your drive) press the Y key
Wait for your USB flash drive to be erased (you’ll see the progress via % values appearing within the Terminal window)
Once the erasure is complete, you will see a prompt that files are being copied to the disk. This may take a while, so be patient.
Eventually the copy process will be over and you should see a Done message in Terminal. You can now quit Terminal.
Now launch Parallels.
Go to File > New (or press commandN)
In the window that appears, select the Install Windows or another OS from a DVD or image file option
Click on the Continue button at bottom right
At the next window, ignore what Parallels is searching for and click on the Continue button again
At the next window, give your virtual machine a name and select the location you want it created in
Now, click on the checkbox to indicate you want to Customize settings before installation
Click on the Continue button
Parallels will now create your virtual machine
When complete, you will be presented with the configuration settings
Click on the Hardware tab
Select the Boot Order option in the left hand list
On the righthand side, tick the Select boot device on startup checkbox. This is a temporary, but critical step!
Feel free to configure your other settings for the virtual machine 
Once you’ve configured everything, exit the configuration screen
Click on the Continue button
You should see a message that your virtual machine is starting. Wait until you see the Boot Menu appear (it’ll probably be a grey screen with blue and black text on it).
The Continue option will probably be selected. Ignore this and use your down arrow key to select the Boot Maintenance Manager option
Press return
Once the Boot Maintenance Manager window appears, use your down arrow key to select the Boot From File option
Press return
Once the File Explorer window appears, use your down arrow key to select the second file listed
Press return
In the next window, use your down arrow key to select the .IABootFiles option
Press return
In the next window boot.efi should be preselected
Press return
Shortly the Apple logo should appear on a black screen


Now you can follow the prompts to install macOS Sierra. 

NOTE 1: - Once you’re within the Boot Menu screens (i.e. Steps 34 - 44) you can press the ESC key at any stage to go back to the previous screen if you need to.

NOTE 2: - Please be patient - the macOS Sierra installation process can take a long time within a virtual machine!

NOTE 3: - Once you're all set up, you will want to go back into the configuration settings for your macOS Sierra virtual machine and uncheck the Select boot device on startup checkbox you ticked at Step 30.

NOTE 4: - If you get stuck at any stage, feel free to post a comment below.