[Device Reviews and Information] chirameto:
My friend, I used to be as confuse as you do.

The best way is to make things very simple. Don't do dual boot. Don't keep any file, use separate empty HDD.

Don't mind multiple boot choices, just use the one that works. Don't try on VM, it won't work even you successfully install.

(Of course you can do everything I just said don't if you understand what you are doing.)

If you still not sure, read on. I will try to guide you through this in detail. So the devs can focus his work on developing this firmware.

Please noted that some part of my guide will contain information for advance configuration in bracket. It's not required.

Installation have three stages. You can skip if you have already done it.

Stage one: Prepare android TV flash drive

Download ISO.

Use this ISO to create bootable flash drive with Rufus

For the partition scheme (choose one):

3.1 For modern computer, you can select GPT partition scheme for UEFI. (recommended)

3.2 If you want to ensure compatibility with old computer, select MBR partition scheme for BIOS or UEFI.

(note: if you choose MBR and use it on modern UEFI PC, you will see 2 bootable choices, both UEFI and non UEFI. Don't mind that, Any choice will do.)

Test by booting from flash drive. If it doesn't boot, retry step 3 with other partition scheme.

Don't do any installation just yet. We will need to prepare you internal HDD first so abort and shutdown your target PC.

Stage two: Prepare internal HDD of target PC

Create a linux live CD or USB, Ubuntu is the easiest to find. (To create bootable live USB, use Rufus with the same steps as creating Android TV USB.)

Boot your target PC with live CD and choose Try Ubuntu without installing.

Once Ubuntu loaded, open Gparted.

Use Gparted to delete all your existing partition on target internal HDD.

Create new partition scheme (choose one):

5.1 If you have modern computer, choose GPT.

5.2 If you have older computer, choose MSDOS (MBR)

(note: if you choose MSDOS and use it on modern UEFI PC, you will see 2 bootable choices, both UEFI and non UEFI. Don't mind that, Any choice will do.)

Create two new partitions.

6.1 First partition, use FAT32 file system, size 500MB (if you have limited space, 100 MB and above is ok), name it EFI

6.2 Second partition, use EXT4 file system, use all remaining space, name it Android

Click apply. Wait until complete. Now you should have 2 partitions, sda1 with FAT32 and sda2 with EXT4.

Stage 3: Installing Android TV

Restart your target PC, this time boot with Android TV flash drive.

On Boot menu, choose install.

Choose install to sda2 (your EXT4 partition) when prompted.

Choose Not format (you have already formatted, besides current ISO seems buggy, it will not actually format your sda2)

When you have been asked to install GRUB2, say YES. Otherwise you will not be able to boot from HDD. (for anyone with dual boot configuration with linux, just say NO)

When you have been asked to format boot partition (in this case sda1 with FAT32), say YES. You have nothing to lose.

(note1: again current ISO bug, at least for me. If I choose not format, installer will not create Android TV boot menu entry for me. All the necessary boot files seems to be copied properly though)

(note2: anyone doing dual boot, DON'T format your EFI. Otherwise your current OS will fail to boot. Instead, boot linux live USB and use efibootmgr to create new entry manually.

To make system read write, say YES. (If I said no here, TWRP seems to fail installing future update to my system partition.)

For the last question to Run or to Reboot. I choose Reboot to see if my HDD can boot Android TV properly.

That's it. You can enjoy your new android TV.

If you followed my guide and your android TV stuck at boot, i'm afraid your PC may not be supported.

You may have to confirm your PC spec with others here in this forum.

Cheers