Computer Spontaneously restarts

[cassiopeia2]

I've been having problems with y computer spontaneously restarting.  it used to do it several times a year, but the frequency has increased to about once a day.  I've run all the standard software and hardware checks and all come out without any known problems.   

The only thing I can think of is dust accumulation on equipment causing it to overheat (would that have been detected in hardware check?)  the transformer input between mains and computer or sensitivity to changes in the mains voltage.

[Hawks_Eye]

Hi @cassiopeia2 

Welcome to the HP Support Community! We're here to help you get back up and running.

I’m really sorry your computer has been restarting more frequently—it’s genuinely disruptive, especially when everything else seems to check out fine. You’ve already done a thorough job running diagnostics, and I appreciate the care you’ve taken. 

Let’s explore a few deeper possibilities that might explain what’s happening and how to stabilize it.

 

Possible causes and steps to address spontaneous restarts

 

1. Thermal buildup and dust accumulation

• Overheating due to dust in fans, vents, or heatsinks can cause shutdowns or restarts.
• Most hardware diagnostics check temperature sensors but may not detect airflow blockages.

What to do:

• Power off and unplug the system.
• Open the case and gently clean all vents, fans, and heatsinks using compressed air.
• Ensure the CPU and GPU fans spin freely and are not obstructed.
• Recheck thermal paste if you're comfortable doing so or have support.

 

2. Power supply instability

• Voltage fluctuations or a failing PSU can trigger restarts.
• External transformers or surge protectors may also contribute if they’re aging or overloaded.

What to do:

• Try connecting the computer directly to a wall outlet (bypassing surge protectors or UPS units).
• If possible, test with a different power cable and outlet.
• Consider using a basic voltage stabilizer if your area experiences frequent fluctuations.

 

3. Driver or firmware conflicts

• Even if diagnostics pass, outdated firmware or unstable drivers can cause intermittent reboots.

What to do:

• Go to Settings > Windows Update > Advanced options > Optional updates and install any listed driver updates.
• Visit your HP model’s support page and check for BIOS or firmware updates:
  HP Software and Driver Downloads

 

4. Windows crash logs

• Windows may log restart causes in the Event Viewer.

To check:

• Press Win + X > Event Viewer.
• Go to Windows Logs > System.
• Look for entries with “Kernel-Power” or “BugCheck” around the time of the restart.

Let me know what you find or if you'd like help interpreting the logs. You’re doing everything right by observing patterns and staying proactive. I’ll be here to guide you further if needed.

If my response helped, please mark it as an Accepted Solution! ✅ It helps others and spreads support. 💙 Also, tapping "Yes" on "Was this reply helpful?" makes a big difference! Thanks! 😊

Take care, and have an amazing day!

Regards, 

Hawks_Eye

[cassiopeia2]

Hi,  Hawks_Eye, thanks for replying.  Checking the inside for dust would have been my first port of call having had a similar problem with a laptop in the past. However, my computer is an all in one HP Pavillion (probably 23.8 inch from measuring it).  What that means is that there are no screws.  Have you any idea how to safely open it?  

[Hawks_Eye]

You are welcome @cassiopeia2 

Thanks for following up—and I’m really sorry this restart issue is still affecting your HP Pavilion All-in-One. You’re absolutely right to suspect dust buildup, especially given your past experience. These systems are compact and sealed, so accessing internal components requires extra care. 

I’ll guide you through a safe approach to inspecting and cleaning the internals.

How to safely open an HP Pavilion All-in-One (23.8-inch class)

1. Prepare your workspace

• Power off the computer and unplug all cables.
• Place it screen-down on a soft, clean surface (like a microfiber cloth or towel).
• Use a plastic pry tool—not metal—to avoid damaging the casing.

 

2. Locate hidden access points

• Most HP All-in-Ones use snap-fit rear panels with hidden latches.
• Look along the bottom edge or near the stand mount for:
  • Rubber feet or covers hiding screws
  • A seam where the back panel meets the frame

Some models have screws under the stand or hinge cover. If present, remove those first.

 

3. Release the rear panel

• Use a plastic pry tool to gently separate the rear panel from the frame.
• Start at a corner and work slowly around the edges.
• You’ll hear soft clicks as the latches release—avoid forcing or bending the panel.

 

4. Inspect and clean internal components

• Use compressed air to clean:
  • CPU and GPU fans
  • Vents and heatsinks
  • Power supply area
• Avoid touching the motherboard or cables directly.
• If the fan blades feel stiff or noisy, note the model number for possible replacement.

 

If the panel won’t open or feels risky

• You can still clean external vents thoroughly using compressed air angled into the intake and exhaust areas.
• If the fan noise or restart behavior persists, consider having a technician perform a full internal cleaning and thermal check.

Let me know how the system responds after cleaning or if you’d like help identifying your exact model for more tailored disassembly steps. 

You’ve done everything right by staying observant and cautious—I’ll be here to guide you further if needed.

If my response helped, please mark it as an Accepted Solution! ✅ It helps others and spreads support. 💙 Also, tapping "Yes" on "Was this reply helpful?" makes a big difference! Thanks! 😊

Take care, and have an amazing day!

Regards, 

Hawks_Eye

[cassiopeia2]

This opening procedure sounds rather complicated and liable to result in damage, so I will attempt the other possible solutions to start with.  I've already plugged it into a separate socket, so I'll see if that works.  If it reboots again I'll find the logs, although it's not the first time I've attempted this.

The last time I attempted to identify the problem from the log entry was two years ago when it was only rebooting every 6-7 weeks rather than once a day as now.  ntoskrnl.exe. was one of the files.  It might be easier to link to the tech help page  I was asking advice on  so you can see everything I've tried already.  This has reminded me I have asked HP before about this.   It has just got more frequent.

[cassiopeia2]

Thanks, I will attempt to remove the panel only if everything else fails because it sounds rather tricky.   

I've plugged it into a completely different socket for the time being, so I'll see if that works.

With regards to log files, I remember asking about this on another tech forum several years ago. Rather than attempt to explain what I did, I'll link to the page which includes the logs.

https://forums.moneysavingexpert.com/discussion/6420598/computer-spontaneously-restarts/p4

[Hawks_Eye]

Thanks for replying @cassiopeia2 

Based on your linked forum thread, the spontaneous restarts appear tied to system-level crashes involving ntoskrnl.exe, IRQL_NOT_LESS_OR_EQUAL, and possibly prm.sys, which point to driver instability, memory faults, or power delivery issues.

Thank you for sharing the link—it’s incredibly helpful. You’ve done everything right by documenting your steps and observing patterns over time. Here’s a focused breakdown of what the logs and discussion suggest, along with next steps to help stabilize your HP Pavilion All-in-One.

 

What the logs and forum thread reveal

• ntoskrnl.exe: This is the Windows kernel, and while often flagged in crash logs, it’s rarely the root cause. It typically signals a deeper issue with drivers, memory, or hardware.
• IRQL_NOT_LESS_OR_EQUAL: This error suggests a driver or hardware component is trying to access invalid memory. It’s often caused by:
  • Faulty or outdated drivers
  • Bad RAM or memory slot contact
  • Power instability
• prm.sys: This may be related to HP’s power or performance management modules. If corrupted or misbehaving, it could trigger restarts during idle or wake transitions.

 

Recommended next steps

1. Run memory diagnostics

Use Windows Memory Diagnostic or MemTest86:

• Press Win + R, type mdsched.exe, and press Enter.
• Choose Restart now and check for problems.
• Let the test complete and note any errors.

If errors appear, reseating or replacing RAM may help.

 

2. Clean boot to isolate software conflicts

• Press Win + R, type msconfig, press Enter.
• Under Services, check Hide all Microsoft services, then click Disable all.
• Go to Startup > Open Task Manager, disable all startup items.
• Restart and monitor for restarts.

This helps determine if third-party software is contributing.

 

3. Update or remove suspect drivers

• Open Device Manager.
• Look for any devices with yellow warning icons.
• Right-click and uninstall prm.sys-related entries if present.
• Reboot and let Windows reinstall clean drivers.

If prm.sys is part of HP software, reinstalling HP drivers from HP Software & Driver Downloads may help.

 

4. Run DISM and SFC to repair system files

Open Command Prompt as Administrator and run:

DISM /Online /Cleanup-Image /RestoreHealth SFC /SCANNOW

These commands repair corrupted system files that may trigger kernel crashes.

 

5. Monitor Event Viewer for Kernel-Power logs

• Press Win + X, select Event Viewer.
• Go to Windows Logs > System.
• Look for Event ID 41 or BugCheck entries around restart times.

These entries help confirm whether the system is crashing or losing power.

Let me know what you observe after these steps. If the issue persists, we can explore disabling hibernation or testing with a clean OS image. You’ve done everything right by staying persistent—I’ll be here to guide you further if needed.

Regards,

Hawks_Eye

[cassiopeia2]

Hawks_eye

It'll take some time to perform those checks (possibly again?).  I've certainly carried out all the standard HP software and hardware checks this week using the latest HP software. Everything comes out 'passed' with the possible exception of the USB ports, although it depends what device they are attached to. It sometimes fails with my android phone but always passes with a USB stick.  Since the restart problem occurs when nothing is attached, not even a cable, I doubt if the restarting is a USB issue.

It restarted today at 14:57 so I have the specific logs you asked for for this event.  Note: this was when the computer was powered down in standby mode, and it was also connected to a new socket so I expect that eliminates many factors.   I will get on with those checks! 

[cassiopeia2]

I've gone through 1 to 3, do I need to re-tick the microsoft applications I've unticked? 

I'm afraid you have lost me regards item 4 and 5.  However I think I've already completed 5 in the logs I've sent you on the unscheduled restart

 Item 4 seems to require an elevated command prompt, but I keep going round in circles and I'm sure the program I downloaded from HP would have covered this, it seemed to go through everything possible.

[cassiopeia2]

Just to summarise these are the faults when it spontaneously restarted at 14:57 yesterday

Error   Volmgr 162   14: 57:37

Critical   Kernel-Power   41   14: 57:37

Warning   Kernel-PnP  41    14: 57:37

Error EventLog    6008    14:57:51

Error Net Log On   3095   14:57:54

Error BugCheck   10001    14:57:56

Error Service Control   7000   14:59:56

Error Service Control   7000   14:59:56

Error TPM-WMI 18101    15:02  

Error TPM-WMI 18101    15:02

I hope that is useful.  

I had another unscheduled re-start later of in the day, this which contains volmgr and Kernel Power errors. 

The following faults don't seem to cause a restart but I can see them throughout the day:  Distributed com, TPM WMI Service Control, Netlog

Searching the Web, I note this user seemed to be getting the same problem and had to replace the motherboard.  I might as well buy a new computer than do that, especially considering how hard it is to open.

https://learn.microsoft.com/en-us/answers/questions/4318415/windows-11-volmgr-162-kernel-power-41-bs...