After 3 years, a sudden "Reboot and Select proper Boot device"

Can you please use the checking for errors option on the 'repair my computer' tab on the install disk?

Hi Laith, I don't get that option from my Win 7 install disk. I had to Google 'Repair my computer', I see some references to 'Repair your Computer' that's available if I F8 to Advanced Boot Options, but mine doesn't offer it.

Chkdsk /f was no luck, fwiw.

When you choose your language and region in install, click next. After that in the bottom left corner you will see an option called 'Repair my computer' click that and in the box it displays click "Check for errors".

i spoke too soon, it's only booting from the windows disc!

Which means it's booting from your harddrive? I'm confused.

Sorry to hear that Nick.

Laith, from 'Repair your Computer' it leads me to a dialog box to choose my drive and OS (C:, Windows 7, Samsung), and a choice to use Recovery Tools or restore from earlier image. When I select the recovery tools option, I get the System Recovery Options with Startup Repair, System Restore, System Image Recovery, etc. There is no option to 'Check for Errors'? I have been selecting Startup Repair, which returns quickly with 'could not detect a problem'.

Select your OS drive and snap a picture of the options.

It's the same as the dialog box shown at this link, except "Microsoft Windows on (C: ) Samsung"

What are the system recovery options in Windows? - Windows Help

Bogey splashed, ThrashZone. Cheers!

Summary: Microsoft update KB3133977 clobbered ASUS mobo's that use Microsoft Secure Boot by default. The workaround is to disable Secure Boot.

After Googling a bit, I found the following guide on Asus forums that was an excellent description and walkthrough. It's essentially the same instructions as post #6 at the link Thrash posted, but with pictures of the BIOS. https://www.asus.com/nz/support/FAQ/1016356/

It did not work for me at first - the additional step I had to take was to go under the option above Secure Boot, called CSM (Compatibility Support Module), and under "Boot Device Control", change "UEFI + Legacy" to "UEFI Only".

Thank you to all the folks that helped! Nick, fingers crossed this brings you out of the woods as well!