SOLVED Can't fully remove Windows from IMac

[Arash]

Hi. I run into a problem while trying to reinstall my Mac OS, but first things first.
I had Windows running on my IMac with bootcamp for a long time. Then one day I realized that there is no bootcamp on Windows and I could't get on to Mac OS so I've used recovery tools to erase a Macintosh drive where was Windows sharing this hard drive. While trying to reinstall Mac OS within recovery tool there is an error occuring saying it wasn't possible to do that. I've created bootable flash drive with Mac OS but my IMac doesn't see this. It's shown in disk manager in recovery tools but it won't boot from this. For me it seems like it's somehow stuck on Windows and have no idea what I could do about that. I'm attaching some images for you to better understand what's going on. I hope someone could give me some advice
Thanks in advance

 

[MacsBug]

The Windows boot files sit on a hidden Partition called EFI. When you erased the drive, you only erased the volume, and not the whole drive.

In Disk Utility if you hit "Command 2" you will see the Apple Drive. If you erase the full drive then you will not see the option to boot into Windows.

The Issue with not being able to install the OS may be a corrupt installer. You may want to download and create a new install drive.

Without knowing which iMac you have, and what the exact error is then its hard to give any better suggestions than this.

 

[Arash]

Thanks for your advice. First part has helped with remaining windows files. It's no more booting in windows. On the pictures it shows how it looks now.
For installing new Mac OS while trying in recovery tools via internet there is all the time the same error.
For bootable flash drive, is there any place I can download installer for High Sierra on Windows ?
I haven't access to any Apple device.
That is serial number : DGKX3HJJ1GN
I hope ths helps as I'm not sure about hardware and exact model.

 

[MacsBug]

Hi Arash,

At this point its an easy fix.

On the very top right of the screen you should see an Airport icon. You just need to connect the iMac to your network before running the installer.

Good luck with this.

 

[Arash]

The thing is it's connected to my WIFI and the error still occurs

 

[MacsBug]

If your connected to the network, and still getting this message, most likely the date and time is not setup properly on the iMac.

You can change the date and time from the recovery by selecting Terminal under the Utilities menu.

Once in the Terminal, type in Date. It should show todays date and time.

If it doesn't then type the following into terminal. Date 050714002023 Then press enter.

This will set the date to today at 2PM.

Quit the terminal and run the installer again.

 

[Arash]

Unfortunately the date was correct. Still the same problem

 

[MacsBug]

At this point the only thing to try is to download a new installer and create a new bootable install drive.

You can download the installer at https://itunes.apple.com/us/app/macos-high-sierra/id1246284741

You will need to be on a Mac that can run High Sierra in order to download this. You can then create an installer from the download. I prefer using an app called DiskMaker X (https://diskmakerx.com) to do this.

 

[Arash]

Thanks a lot for your time. I'll try to get access to other Mac then

 

[Alan B]

It may be possible to perform a reinstall over the Internet. Start up or restart your Mac holding down the Option-Command-R keys at the same time to start this process as described here:

https://support.apple.com/en-gb/gui...and-R: Start,macOS Recovery over the internet.

 

[Arash]

All set up. Thanks guys for your help