Windows can't find specified partition - iMac 2017 27"

The missing <ImageInstall> tag is due to a corrupted AutoUnattend.xml file. If you are on a 2017 Mac, it is rebuilt overtime you try to install Windows. There are several reasons why this happens. Your source ISO may be corrupt, the BC Windows Software download failed silently. BCA failed to merge the ISO and the BC drivers.

In Terminal, can you run

diskutil list

and check if you have a OSXRESERVED partition? If you do, the file is on that partition. It can be opened in TextEdit and reviewed. You can search for the tag value and check what in there. Also, you should see a list of valid partitions, which depend on the value of another tag in the same file. See Re: Re: Re: Bootcamp install windows to black screen for an example, which can be edited, but your model does not allow that. See Windows cannot locate the disk and partition specified in the unattend answer file's <ImageInstall> setting. as an example.

Can you disconnect all external storage and hubs and run

How to reset the System Management Controller (SMC) on your Mac - Apple Support

How to reset NVRAM on your Mac - Apple Support

and then retry BC Assistant? Previously failed installations are an issue, in this case.

Your 2017 Mac should not have any external storage or hubs connected. The 2017 Models build OSXRESERVED every time you run BC Assistant. Run SMC/NVRAM reset after you disconnect all external storage.

Can you post the output of

diskutil list

Hello, I am having the same issue.

Error 'Windows cannot locate the disk and partition specified in the unattend answer file's <ImageInstall> setting. Make sure the setting references a valid partition and restart the installation.'

I did not locate 'OSXRESERVED partition' when inputting into Terminal.

macOS 10.13.2 > 1TB Fusion Drive > iMac (Retina 4K, 21.5 in., 2017)

I do not know how to open the 'AutoUnattend.xml file' and make changes to the portion below:

<ImageInstall>

<OSImage>

<InstallToAvailablePartition>true</InstallToAvailablePartition>

</OSImage>

</ImageInstall>

<DiskConfiguration>

<WillShowUI>Never</WillShowUI>

</DiskConfiguration>

(Don't know if it is Never or Always since I do not know how to open it.)

Have reset SMC and NVRAM > disconnected all external drives.

Ended up loosing quickbooks in the process of all of this. I restored time machine back up. Now I'm starting over with the bootcamp assistant.

Are you using Boot Camp Assistant to attempt to install? If you are then please post in the Boot Camp forum.

I took care of it for you.