Cannot install Windows 10 via Boot Camp (more space required error)

[Suddhodana]

Hello!

I have a problem installing Windows 10 on my late 2015 iMac via Boot Camp. I downloaded the ISO from Microsoft and I am using the Boot Camp Assistant to create a partition. So far so good. Now when the Windows installer starts, I choose the newly created partition. Now the problem starts: I doesn't matter what size I chose for the partition with the Boot Camp Assistant (I tried 50 GB, 100 GB, 150 GB and even 200GB) I get the following error message: "Setup was unable to use the existing partition because the system volume does not contain the required free space". Like I said, it even happens with a 200 GB partition. Normally that should be more than enough for Windows 10.

Anyone has an idea what the problem is?

Thanks for the help!

 

[chscag]

Is your iMac hard drive a Fusion drive? It appears that it is according to your partition list. You may need to do some research on how to setup Boot Camp on a Fusion drive. My iMac drive is an SSD so I have no experience with installing Windows on a Fusion drive.

 

[Suddhodana]

I am honestly not sure (how can i check it?), but shouldn’t the Boot Camp Assistant account for that?

I read somewhere else that the EFI partition could be the problem for some reason because it is too small. Any ideas how to fix that?

 

[chscag]

Use your System Information app to find out about your hardware. You can also click on your Apple menu and select "About this Mac", and then select Storage. A Fusion drive consists of a smaller flash drive combined with a larger spinner type. They are then "fused" together.

I don't know if the Boot Camp Assistant accounts for that or not. However, the problem doesn't appear to be with the BC Assistant but rather with the Windows setup. I'm guessing that the Windows setup is trying to install on the wrong partition instead of the one you created.

 

[Suddhodana]

It was the EFI partition that was full for whatever reason. For future reference I will leave a link that helped me:

https://apple.stackexchange.com/que...ng-bootcamp-system-volume-doesnt-contain-requ