Older MB sometimes boots to EFI rather than to Windows

I have an older computer with a 4th gen Intel i7. Detailed specs are below, but before I begin, I just wanted to point out that, while I realize that this is not a technically supported system by Windows 11, this same problem happens with Windows 10. In fact, since the problem happens before loading the OS, I'm confident that this is not even a Windows problem, but a HW or BIOS setting problem of some sort. Just wondering if anyone else has seen this symptom and knows of any specific items to check.

Detailed Hardware Specs

Motherboard: MSI Z97 MPOWER MAX AC
CPU: Intel i7-4790K
Video: Using only the onboard video, no GPU
RAM: 32 GB
TPM: TPM 1.2 module (not 2.0)

Storage:

1 x 512 GB XP941 M.2 drive used as boot disk
1 x 4 TB HDD
5 x 8 TB HDD
1 x Blu-Ray Reader / Writer optical drive

PCIe Expansion Cards:

1 x 2 Port USB-C adapter.
1 x Realtek 2.5 Gbps Ethernet adapter (used in place of the 1 Gbps Ethernet on the MB)

END SYSTEM SPECS
----------------------

Problem Description:

Sometimes, when I boot the system, it will fail to boot Windows, booting to the EFI shell instead. This is extremely difficult to reproduce, it just happens at completely random times. It can happen both from a cold boot and from a reboot.

If I had to guess, I would say that it happens maybe once every 20 boots or so as an average.

Please note that I have always had this problem, although it seems to me to be more frequent now. It also happened back in the old days before I had an M.2 SSD installed on the MB.

Things that I have tried:

I have disabled all forms of fast startup in the BIOS.
I have made certain that all overclocking settings are turned off.
Test RAM - all tests pass.
Ran system with only the boot disk, same problem.
Reset the BIOS to defaults and reconfigured from there.
Verified that I have latest available BIOS.

Any ideas on what I might check? As noted, this has plagued me for years, but I thought I would make one last effort by posting here to see if anyone has ideas I may not have tried.

hsehestedt said:

Any ideas on what I might check?

Click to expand...

Here's the link to your manual (pdf)...



I would check these things in the RED boxes. I can see where any of these "might" cause weird problems, if the switches involved are going bad or are partially... stuck, etc.



The page following the page with this pic, has the page numbers for the individual item's descriptions.



Also... it would probably be a good idea to get a new CMOS battery. CR 2032
You can get them at drug stores, stores like Walmart, Home Depot or jewelry stores, camera stores, etc.
Last time I checked they were about 7-8 dollars.

All of those items have been checked already. I did some more research, and it seems that some other systems with the Z97 chipset have the same issue. At least one system has a BIOS option to introduce a boot delay which solves this problem. My BIOS has no such option; however, I was thinking that I could introduce a delay by setting the system to boot from flash drive and then after a timeout have the system boot from the HDD.

I could create a Windows boot disk on a DVD. The system would start to boot from it, but when no key is pressed, it would then boot from the HDD. However, I would ultimatly like to get rid of the optical drive and use a USB flash drive instead. The only problem is that when you boot Windows setup media from a UFD, it does not ask you to press any key to continue.

Anyone know of a way to create a UFD that times out and then boots from the HDD?

Does this young thread not bear a resemblance to this older thread


FWIW, one of my machines has always had a similar issue, i.e. a hiccup in the boot process > starts to boot > pauses for a second (the screen blanks out) > continues to open the machine normally.

Of course, I disabled fast start, hibernation, ran DISM commands, sfc /scannow etc etc but I don't bother with the hiccup any more, since there are no other issues, it is in fact a very good machine.

it is most likely a usb device causing the issue, it is not broken, just causing confusion with the motherboard.

Not really similar. In my case, when the issue happens, it doesn't even start to boot from the drive. It simply boots right to the EFI shell.

I'm starting to think that I may need to setup a watchdog timer to reset or power cycle the system when this happens.

@hsehestedt Oops, I completely missed your point

@retiredat44 Thanks for the tip, I'll follow up when I feel like plugging/unplugging in inaccessible USB ports

Haydon said:

@hsehestedt Oops, I completely missed your point

Click to expand...

No worries. It's an odd issue .