Good People,
What am I doing wrong?

I make a system image backup in Win 8.

A .VHDX file is created.

I can not mount this file.

I can mount a VHD file.

vhdx should mount in explorer like vhd or iso, but since this is a pre-beta who knows? Try attaching it in disk management. Open the disk management window, click on Action menu at the top, click Attach vhd.

Bill,
Have already tried those and any other variant I could think of.

Have also run sfc.

Have you mounted a vhdx file produced by win 8?

Nope, I don't have a vhdx right now and I aint making one cos I'm waiting for beta.

I've already gone thru one complete reinstall from the ground up and was hoping that the win 8 backup/restore worked.

Do you know when we can expect the beta or even an alpha. This version is extremely premature.

TBH, there are all kinds of predicted dates ranging from oct to feb, depends on who you want to believe in. Plus when and whether a public beta will be released.