Windows 8.1 on WIndows 8.1 host - install error (CD-ROM)

[oliver-h]

Hello,
I'm new to VirtualBox.
I am trying to install Win 8.1 32bit on a Win 8.1 64bit host with VirtualBox 4.3.26.
I first had a iPXE error when trying to use an .iso to install Windows, so I mounted it with daemon tools and installed the extension pack.
Now I get a critical error with "ata1 master: VBOX CD-ROM ATAPI-6 CD-ROM/DVD-ROM" shown in the screenshot.
Please see the log:

VBox.zip

Log

(40.04 KiB) Downloaded 5 times

Any ideas?
Thank you!

[scottgus1]

Best of my knowledge, a new guest defaults to booting from the virtual CD drive first (check guest's Settings, System, Motherboard, Boot Order) , then loading the ISO into the virtual CD drive (check guest Settings, Storage, click the virtual CD drive, click the dropdown CD icon on the far right, choose a virtual CD/DVD, browse to your ISO). Start the guest and the CD boots up if the ISO is good and bootable. No PXE stuff needed, nor do you need virtual CD drive software on your host. Virtualbox reads the ISO directly.

Try again, loading the ISO as above, not using any PXE or the Daemontools, and see what you get.

[oliver-h]

Thanks for your help!
I tried what you said, but it didn't solve the problem.
So I looked in the log and found some VERR_VMX_INVALID_VMXON_PTR error, which made me find ticket 9748 (not allowed to post links yet, sorry).
So I disabled VT-x/AMD-V and now everything works fine.
Thanks again!

[mpack]

I don't see how that can have helped... Windows 8.1 requires VT-x!