Working Windows 10 suddenly won't load (four blue squares then reboot)

I've had some fun and games with Windows 10 so far (Solved Windows 10 upgrade - random freezes and PC becomes unresponsive - Windows 10 Forums), and this forum has helped me get back on my feet. Now something else seems to have gone wrong.

I was fiddling around with the BIOS last night (trying to get the PC to see 8GB rather than my current 6GB of memory). Anyway, I couldn't, so I switched all the BIOS settings back to what they were (even did a CMOS reset). However, I now find that my PC won't boot into Windows 10. It crashes/reboots as soon as the four blue squares appear on screen (usually before the little dots even have time to rotate).

I can't boot into Safe Mode. Inserting a Windows 10 DVD also falls over. Even the Macrium Reflect boot disc I have won't work. However - mine is a dual boot machine - it will boot into Windows 7 without a hitch.

I've tried using the BoYans.net Dual-boot Repair tool, but no no avail. Ditto Tenorshare Windows Boot Genius - though it does at least boot, but none of the tools within it have made any difference (I've tried Boot File Recovery and MBR Recovery - I didn't run Boot Sector Recovery, as it mentions making "All boot sectors of this partition... compatible with Windows Vista and Windows 7".)

Can it possibly be something weird in the BIOS - even though I've reset it on more than one occasion? Or is it, as I suspect, some weird boot problem (again!) - both the above tools can see the Windows 10 installation, so I know it's still there in theory.

Any advice, gratefully received. Thank you kindly.

Assuming you have Win 7 first then dual boot with Win 10.
My suggestion only :
Logon to Win 7 OS > run diskmgmt.msc > Remove Win 10 Volume > Extend volume back to Win 7.
Recreate a new partition > install Win 10 into the new partition.

Will that be workable ?
Will it get activated afterwards ?

WightWalker said:

I wouldn't have thought that modifying settings in the BIOS would create this problem, but then I've had Windows 10 Pro crash twice for no reason.

First was the very next day after a clean build - worked perfectly prior to shutting down. Nothing worked to rebuild the system. Luckily, I had created a Macrium backup which worked perfectly.

Secondly after doing an update, a re-boot was requested it would just not reboot behaving as in the previous instance. Macrium again came to the rescue.

Never had these unexplained boot up problems with Windows 7.

Sorry couldn't help but though you'd like to know that you're not alone!!

It does help! This is the second boot problem I've had with Windows 10 - and in both cases, I could continue to boot into Windows 7 without a problem. Did they change the way Windows 10 boots? Is it somehow much more flaky?

billy268 said:

Assuming you have Win 7 first then dual boot with Win 10.
My suggestion only :
Logon to Win 7 OS > run diskmgmt.msc > Remove Win 10 Volume > Extend volume back to Win 7.
Recreate a new partition > install Win 10 into the new partition.

Will that be workable ?
Will it get activated afterwards ?

I believe activation wouldn't be a problem - I think Windows 10 just checks for any valid Windows OS install on the PC. But I think what you're advocating would/might allow me to do a new install of 10. Obviously, I want to hold off the thermonuclear option for as long as possible, as I know my Windows 10 is (somewhere, somehow) on my PC complete with all its Windows 8/8.1 and recent customizations. But thanks for the suggestion.

Right, I've been fiddling with this all weekend and am no further forward. So I thought I'd post an update in case anyone has some blinding insight...!

Back to basics: I have Windows 7 installed on (let's call it) an old D: drive. I have Windows 10 installed on a newer SSD (a recent upgrade to a fresh install of Windows 8.1 that dates back to last year) - let's call that C: (I also have a big E: drive for documents, but let's ignore that for the moment.)

The Dual Boot Repair tool confirms two OSes installed. Windows 7/2008 R" (32-bit) 6.1.7601.17514 (win7sp1-rtm.101119-1850) on D:, and Windows 10 (64-bit) 10.0.10240.16545 (th1.150930-1750) on C: (which is set as default).

(I also have various BCDs saved with EasyBCD, but when restored, none of them allow me to boot into Windows 10. EasyBCD also confirms the same two bootloader entries. It also shows that the Windows 10 drive is set to C:, and the bootloader path is set to \Windows\system32\winload.exe; the Windows 7 drive is set to D:, and the bootloader path is set to \windows\system32\winload.exe)

If I try to boot into Windows 10 when given the option, the four blue squares appear (and sometimes the little circles start to spin around), but then it crashes and immediately restarts.

If I select the various F8 settings (1. Enable debugging, 2. Enable bootlogging, 3. Enable low resolution video, 4. Enable Safe Mode, 5. Enable Safe Mode with networking, 6. Enable Safe Mode with Commmand Prompt, 7. Disable driver signature enforcement, 8. Disable early launch anti-malware protection, 9. Disable automatic restart after failure) from the Windows 10 part of the menu, the same thing happens, i.e. it reaches the four square logo and then reboots. No error messages, with the exception of when I tried 6. I got a blue screen of death with the irq_not_less_or_equal error.

When I insert a known working Windows 10 installation DVD, the four Windows squares appear, and that's it.

When I tried using the Macrium Reflect DVD boot disk, there's nothing on-screen for ages, then the four Windows squares (briefly), then a blue screen of death/sad smiley. The error mentioned is kmode_exception_not_handled (and it needed a full restart).

(I have also used a tool called Windows Boot Genius, which boots into a desktop (based on Win 7?) but doesn't seem to actually fix anything.)

Throughout all this, I've been able to boot into Windows 7 without a problem.

So, in a nutshell, I can't boot into Windows 10. I can't boot into Windows 10 Safe Mode; I can't even use a Windows 10 installation disk to boot and attempt a repair.

And yet, as with last time, I'm 99.99% sure my Windows 10 installation is still there, waiting for me, if only I could access it...

Any thoughts, gratefully received, as I am running out of hair to pull out.

Just 'chatted' to an MS chap who pointed the finger at bad sectors or whatever on my SSD (I guess it would explain why the OS on that drive doesn't work (7 is on another drive altogether), and maybe even why the Windows DVD doesn't work - if it's trying also to invoke something from that drive? I don't know, this is all way beyond my competence...).

I ran chcdsk from Windows 7, on the SSD, and it sure enough found a ton of things to sort out. But on rebooting, I still can't get into Windows 10 (I can see all the files, etc., are there from within Windows 7).

Any ideas?

Please, any ideas, anyone? I've just wasted an hour of my life live chatting to a Microsoft support person who seemed to know less aboout Windows than I do, didn't understand what's happened thus far, and ended up saying my hard drive isn't compatible when it's a Samsung EVo SSD that's been running Windows 8.1 for about a year, and Windows 10 for about a month...

I'm just about at my wit's end.

I finally - after about a month of making do with Windows 7 on my oldest hard drive - have Windows 10 working again. I note my solution here, in case it is of use to someone else in the future (and the least said about Microsoft's so-called support technicians, the better).

I downloaded the MiniTool Partition Wizard 9.1 from Bootable Partition Manger | MiniTool Partition Wizard Bootable Edition and burned a bootable disk. Once I'd booted into that I used it to expand the SSD so it once again spanned the whole volume (there was some empty capacity left over, presumably from an earlier scan on the Samsung drive), and then selected Rebuild MBR.

It then booted into Windows 10 first time. Simple.

Now, I don't know if both steps are needed (I'm guessing it was rebuilding the MBR that actually solved things), and I don't know why my previous and numerous attempts to perform an equivalent process from within Windows 7 didn't work, but there you have it. I'm back in Windows 10 again. Hurrah!

Hi,

Sorry I missed your thread. Still, glad to hear you have it working again.

Just for info though, if you get this "irql not less or equal" message that means that two pieces of hardware are assigned the same IRQ (Interrupt Request) so they can't possibly work together and that causes the system to crash.
This something you can no longer do in Windows (those who have experienced Win 95 may remember these issues all too well) but some bios might and that's at least part of your horror story IMO.

Why it didn't crash on the Windows 7 install I have no clue.

Best,