Windows 11 Stop code: Critical_Process_Died (0xEF) BSOD error

Question

Windows 11 Stop code: Critical_Process_Died (0xEF) BSOD error

Michael 0

Hi there,

I have been having a problem for the past week or two where my laptop will crash randomly and give a BSOD with the Stop Code: CRITICAL_PROCESS_DIED (0xEF) error. It usually crashes after being on for 3-5 minutes, even if I have nothing open and am not actively using it. I haven't been able to figure out what is causing the crash. I have had no issue with crashing before this, I am not sure what caused it whether its a hardware, software, or windows update issue. I haven't installed any new software and I do not remember updating windows right before the crashing started. I have tried updating windows, updating all drivers, updating BIOS (from HP website), booting into SAFE mode, full virus and malware scan in windows defender and malwarebytes, ran RAM and hard-drive scans, ran sfc /scannow, and reinstalled Windows. Nothing has helped. I checked the event viewer and it just says that the computer shut down unexpectedly and failed to create a minidump log. I don't know what else to do. My computer specs are below. Any help is appreciated. Thank you.

Laptop info: HP Spectre x360 Convertible 15-ch0xx

Processor Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz, 1992 Mhz, 4 Core(s), 8 Logical Processor(s)

BIOS Version/Date AMI F.38, 12/8/2022

Graphics Card NVIDIA GeForce MX150 (2 GB), Intel(R) UHD Graphics 620 (128 MB)

Installed Physical Memory (RAM) 16.0 GB

Edition Windows 11 Home

Version 25H2

Installed on ‎9/‎22/‎2026

OS build 26200.9550

Experience Windows Feature Experience Pack 1000.26100.372.0

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2 answers

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Answer 1

Clary-N 16,660 Microsoft External Staff Moderator

Hi Michael,

Thanks for providing all those details. Since you’ve already worked through quite a bit of troubleshooting, I’d like to narrow down a couple of things before suggesting anything more drastic.

When you tested Safe Mode, did the laptop stay running longer than the usual 3–5 minutes or did you get the same BSOD there as well? Also, when you reinstalled Windows, did you use Reset this PC or did you perform a clean installation from a bootable USB and remove the existing Windows partitions?

Since you mentioned that Windows hasn’t been able to create a dump file, could you also check Advanced system settings > Startup and Recovery > Settings and let me know what is currently selected under Write debugging information? Please also check whether the paging file is set to "Automatically manage paging file size for all drives".

I’d also suggest running the Extensive Storage and Memory Tests from HP PC Hardware Diagnostics UEFI, rather than only testing from within Windows. If possible, disconnect any nonessential USB devices, docks, memory cards or other peripherals while testing.

If the laptop also crashes in Safe Mode or continues doing so immediately after a clean Windows installation, particularly if HP’s UEFI diagnostics report a failure, I’d consider having the SSD and other hardware checked by HP or a qualified repair technician. I wouldn’t call this a confirmed hardware failure yet, but at that point there would be relatively little value in repeating the Windows repair steps you’ve already tried.

Let me know what you find from those checks, especially whether the same crash happens in Safe Mode.

Michael 0 Reputation points

2026-09-27T07:29:52.14+00:00
Hi Clary,

Thanks for your reply. To answer your questions:

Yes, I kept getting the same BSOD every 3-5 mins even in safe mode

I did Reset this PC first. When that didn't work, I did a fresh install of Windows from a bootable usb. The various Windows recovery partitions were not removed from the hard drive

Startup and Recovery settings: For Write debugging information, the Complete Memory Dump option is selected from the drop down menu, with the dump file being written to %SystemRoot%\MEMORY.DMP

Automatically manage paging file size for all drives option is enabled

I ran the quick version of the HP UEFI storage and memory checks you mentioned, both passed. I'll run the extensive tests when I get a chance and post the results.

I should mention, sometimes I can get the computer working fine for an extended period of time. It's usually after 4 to 10+ BSOD errors. After doing a fresh install of Windows, the laptop ran for a while without the BSOD before I installed any Windows updates. It started crashing again after installing updates, though it was a different session. It could be a coincidence, and I didn't see this problem on the known issues page, but I will try uninstalling any Windows updates and see if it helps.

Appreciate your help. Looking forward to any other suggestions you may have.
Clary-N 16,660 Reputation points Microsoft External Staff Moderator

2026-09-29T01:46:06.9866667+00:00

Hi Michael,

Thanks for the detailed update. Since the laptop also crashes in Safe Mode and continued doing so after a fresh Windows installation, this is less likely to be caused by a normal startup app, although it still doesn’t confirm whether the underlying cause is a driver, firmware or hardware issue.

Because it seemed stable before Windows Update ran, uninstalling the latest quality update only is a reasonable test. Before removing it, note the KB number and installation date under Settings > Windows Update > Update history. I’d also check Driver updates, since Windows Update may have installed a device driver at the same time. Avoid removing several updates at once, as that would make it difficult to identify which change matters.

For the missing dump, try changing Complete memory dump to Automatic memory dump or Kernel memory dump, restart the laptop and make sure the Windows drive has enough free space.

Please also run the extensive HP storage and memory tests when you can. If either test produces a failure ID, save it for HP support. If both pass but the crashes continue even after removing the latest update, I think HP should inspect the SSD, memory and system board rather than repeating more Windows repair steps.

Let me know what happens after testing the latest update and what the extensive diagnostics report.
Clary-N 16,660 Reputation points Microsoft External Staff Moderator

2026-09-30T08:48:06.2+00:00

Hi Michael,

Have you had a chance to check my answer yet?

Please do keep me updated.
Michael 0 Reputation points

2026-09-30T17:35:04.9233333+00:00

Hi Clary,Sorry I was gone all weekend. I did check your answer, thank you for that. I do have some updates, it's pretty long so bear with me:I performed the HP UEFI extensive memory, extensive storage, and extensive system wide scans. All components passed. The scans were going for 30+ mins without any restarting or errors which seems like a good sign.I tried changing the dump file settings to Automatic memory dump and Kernel memory dump, still no dump files. There is 250 GB of space on the ssd so I don't think it's a storage issue.I uninstalled two Windows updates: 1. 2026-09 Preview Update (KB5124010) (26200.9550) installed on 9/24/2026 and 2. 2026-09 Critical Update (KB5128942) installed on 9/22/2026. Neither of these had an effect. There are 32 driver updates installed on 9/22 and 5 definition updates installed on 9/22 thru present. I could look into these but I don't think they are causing the issue. On the subject of drivers, I did notice some mysterious ones after re-installing windows previously, see photo below (they may have been there previously but I didn't have a reason to check in device manager). I have tried finding drivers for them and also uninstalling them but they keep reappearing. I don't know if they are connected to the BSOD errors but wanted to mention them just in case.

Finally, I think I have found the source of the BSOD errors. It seems to be a thermal issue. There's a fan in the room that I use the laptop. If I put the laptop on the desk/table/whatever surface, the BSOD errors occur every few minutes. If I hold up the laptop in front of the fan, the errors don't occur. I installed HWMonitor to check temperatures. Holding the laptop in front of the fan, the CPU temp stays around 50-55 degrees C. When I put the laptop down, the temps steadily climb up and eventually reach 97 degrees C before restarting. This seems to be the only component that has such a large temperature change. The laptop is a convertible, so the lid can rotate completely around. If I flip the lip around so the screen is still facing me and the keyboard is resting on the desk, the intake vents are now up. Even without a fan, this configuration seems to be stable (of course now I can't type ha). So maybe the intake vents aren't getting enough fresh air. I don't know why I didn't have any issues while running the HP UEFI scans as they were on for a while and had the vents down on the table. I also don't know why this started happening just recently when it's never happened in the years before while using it in the same exact way. Maybe the fans need to be cleaned, or the temperature sensor is broken, or the temperature threshold for shutdown was somehow changed for Windows but not for the BIOS? I don't know, do you have any insight into this? I'm going to open the back and take a look when I get a chance and provide updates. Thank you for your help and guidance Clary, really appreciate it
Clary-N 16,660 Reputation points Microsoft External Staff Moderator

2026-10-01T06:55:34.1633333+00:00

Hi Michael,

Thanks for the detailed update. The temperature testing is especially helpful. Since the CPU reaches around 97°C before restarting, but the laptop remains stable when the vents receive better airflow, this now points much more strongly to a cooling issue than a Windows update problem. The UEFI tests passing is reassuring, but they may not generate the same sustained heat as normal Windows use.

I’d stop uninstalling updates for now. Keep the laptop on a hard, level surface with the vents unobstructed and avoid deliberately reproducing the overheating. You can clean the external vents with compressed air while the laptop is fully powered off and unplugged, but I’d avoid opening it yourself if it’s still under warranty.

The unidentified devices may need the correct HP chipset and system drivers after the clean installation. Install only the BIOS and drivers listed by HP for the laptop’s exact model, rather than using a third-party driver tool.

Given the clear connection between airflow and temperature, I’d have HP or an authorized repair provider inspect the fan, vents, heatsink and thermal contact. As a precaution, back up any important files now. If you notice unusual fan noises, a burning smell, battery swelling or the case becoming extremely hot, shut the laptop down and stop using it until it has been inspected.

Does the fan become noticeably louder or push more air as the temperature rises?
Clary-N 16,660 Reputation points Microsoft External Staff Moderator

2026-10-02T08:37:28.25+00:00

Hi Michael,

May I know if you have got any chance to check my answer?

I am glad to help if you have any other questions.
Michael 0 Reputation points

2026-10-02T21:26:25.5766667+00:00

Hi Clary,

I saw your answer, just haven't had a chance to do much investigating yet. I promise I'm not ignoring you, and very much appreciate your help, I'm just pretty busy over here ha. I should be able to look into this more this weekend, and when I do I will update you here. Until then I'll answer your reply as best I can.

Thanks for the tip about checking with HP for the mystery drivers. I'll look on their website and see what I can find out. The laptop has long been out of warranty so I'm probably on my own repair-wise. I've built a few computers so I have at least a some idea of what I'm doing, well at least enough to know when I'm out of my depth.

My best guess is there is something wrong with the fan or whatever is controlling the fan, though I'll know more when I get some time to investigate. I haven't noticed the fan getting louder or blowing more air out as the CPU temp rises lately. It did in the past and was very audible. I checked the BIOS but the only fan setting is having them on or off (the fan setting was already on enabled). My thought was to use a program to put the CPU fan on full blast to check if it's working. I tried a program I use on my desktop called Fan Control, but it doesn't seem to work for laptops. From a little digging, it sounds like most or all third software won't be able to control laptop fans. HP has a program called Cool Sense that somewhat does this but I don't think this laptop is eligible for it. I don't know of another way to check if the fan still works properly. Maybe removing the fan and plugging it in to my desktop and check it with Fan Control on that computer? I'll use condensed air to clean the laptop vents and the insides in general (I will remove the battery and either remove the fans or block them from spinning when I do this). Hopefully it's the fan dying and not something else. Just glad that it appears to not be an issue with Windows. Anyway, I will let you know what I find. Thanks for sticking with me through all this!
Michael 0 Reputation points

2026-10-05T23:27:15.4933333+00:00

I had some time to work on the laptop, but didn't come up with many answers. Searching around on the internet, it looks like the CPU fan kicking in late is common for the HP Spectre x360 line of laptops. I read many comments that their CPU fan wouldn't ramp up until the CPU is 90+ degrees and already thermal throttling. I remember audibly hearing my CPU fan ramp up but since I never had any issues before I didn't check at what CPU temperature the fan kicked in. One thing I saw in the comments is the BIOS Fan Always On setting is better set as disabled. I ended up doing that and the CPU temperature will rise to 70-80 degrees, the fan will ramp up, and then settle to around 60 degrees. This appears to be stable using it normally like I used to, I don't have to hold the laptop in front of the fan or have the keyboarding facing down. I don't know if this solves my problem entirely but it's been a good start so far.

I wasn't able to test the CPU fan like I thought I could. The laptop fan doesn't have a standard 4 pin fan header connection. I don't recognize the connector so I don't think I'll be able to find an adapter. The laptop fan does work, though it would have been nice to know if it's running at a diminished capacity.

Really the only thing I can think to do at this point is just to monitor it. If I get the critical process died BSOD errors again then I might try replacing the CPU fan and thermal paste. Based on the HP manual, both of these seem pretty easy and non-intrusive. Other than that, I don't think there's much I can do. I'm not sure why the errors started out of the blue. This started happening before I updated the BIOS so I don't think it's that. But whether it's from hardware degradation, possibly running at high heat over a prolonged time for many years (I never monitored temps so could be possible), something new in Windows that changed the temp threshold for shutting down the CPU, or something else entirely, I'll likely never know. Anyway, thanks Clary for your help, it was greatly appreciated. I'm curious if you have any other ideas, but either way thank you very much for all your help. If the laptop remains stable over the next few days, I'll wrap up this post and mark it answered.
Clary-N 16,660 Reputation points Microsoft External Staff Moderator

2026-10-06T09:13:58.5033333+00:00

Hi Michael,

Thanks for the update. It’s encouraging that the fan is ramping up again and the temperatures are settling around 60°C during normal use. I think monitoring it for now makes sense, especially while it remains stable.

If the BSOD returns, checking the temperature and fan behavior at the time should help narrow things down further. Hopefully it stays stable from here and I’m glad I could help.

Answer 2

CRITICAL_PROCESS_DIED (0xEF) means a critical Windows system process terminated. This stop code is commonly tied to driver, hardware, or system corruption issues rather than a normal app crash.

Since these were already tried and did not help:

Windows update
driver updates
BIOS update
RAM and drive scans
sfc /scannow
Windows reinstall

focus on the remaining supported checks below.

Boot into Safe Mode If the system is stable in Safe Mode, that points more strongly to a driver or service loaded during normal startup.
Check Device Manager for hidden driver problems
- Right-click Start > Device Manager.
- Look for any device with an exclamation mark !.
- For flagged devices, try Update driver.
- If that does not help, try Disable device or Uninstall device.
Check Event Viewer around the crash time The 0xEF guidance recommends checking the System log in Event Viewer for critical errors in the same time window as the blue screen. This can help identify a failing device, driver, or service.
Check firmware and manufacturer diagnostics Even with the BIOS already updated, the documented guidance for 0xEF also recommends:
- checking for updated system firmware from the manufacturer
- running hardware diagnostics supplied by the system manufacturer
Run a full malware scan The 0xEF troubleshooting guidance includes running a virus detection program, because disk corruption from malware can contribute to bug checks.
Confirm free disk space Windows guidance recommends keeping roughly 10% to 15% free space available so Windows can create swap files and perform normal system functions.
Use System Restore or Recovery options Since reinstalling Windows did not resolve it, use the recovery options that best match the scenario, including restoring from a restore point if one exists.
If dump files can be collected, analyze multiple dumps Microsoft’s 0xEF documentation states that determining the exact cause typically requires examining dump files, and that multiple dump files should be compared for common characteristics. If the system is failing to create minidumps, that limits root-cause analysis.
Strongly consider hardware service diagnostics When a system has already had Windows reinstalled and still crashes within minutes, accepted support guidance in similar cases recommends a full hardware diagnostic check of the device, not just software troubleshooting.

A practical order for this case:

Test in Safe Mode.
Check Device Manager and Event Viewer.
Run HP hardware diagnostics.
Verify enough free disk space.
Run a full malware scan.
If crashes continue after a clean reinstall and diagnostics, treat this as likely requiring manufacturer hardware service.