How To Check If A Computer Is Overheating With HWMonitor

Overheating can damage the vital components in a computer. Modern computers try to protect themselves from overheating by shutting down before damage can occur.

If this happens to you, don’t ignore it – shutting down can be an early warning sign of serious damage to come if the cause of overheating is not fixed.

Signs Of A Computer Overheating

An overheating computer will typically shut down or reboot (restart) by itself – in more serious cases this may happen just a few seconds after the computer starts up.

Overheating can create software problems too – just like powercuts, such sudden shutdowns may cause corruption in Windows files (e.g. the registry) and stop Windows starting up.

Once the computer has restarted it will likely stay on for even less time (because it is already hot to begin with) e.g. if it shuts down after an hour and you restart immediately, it may only stay on for a few minutes – because the cooling fans can’t dissipate the heat quickly enough.

Other signs of overheating may include random BSOD (‘Blue Screen Of Death’) crashes or increased noise (as fans in the computer have to spin more quickly to try to cool it down).

In a laptop, you may notice that the underneath becomes very hot and sometimes any exposed metal on the side (e.g. a VGA socket) may actually become too hot to touch…

Using HWMonitor To Check If A Computer Is Overheating

HWMonitor (Hardware Monitor) is a free program that reads the main health sensors in computers. It displays the temperatures and speed of fans, as well as voltages and battery power/health.

The program handles the most common sensor chips and can read the thermal sensors found in modern processors, as well as hard drive and video card (GPU) temperatures.

Download the portable (Zip) version of HWMonitor (not the paid Pro version) from the left hand side of the developer’s site here – the portable version is highly recommended as it requires no installation. It is available in 32bit or 64bit versions.

[Note: the installation version may contain additional software e.g. the toolbar/search engine will be installed automatically if you do not opt out. Whereas the Portable zip version doesn’t]

Unzip (extract) the portable Zip file and run the HWMonitor.exe program – after a short delay, the Hardware Monitor program opens.

The current data is displayed in real time (Value) as well as the Minimum (Min) and Maximum (Max) values since the program was opened – this lets you track how temperatures change during use.

An example is shown below:

HWMonitor Check If A Computer Is Overheating

What Do The HWMonitor Values Mean?

Detailed interpretation of the values in HWMonitor may require you to search manufacturer or user forums to find the normal (and maximum) operating temperatures of the components in your own computer.

However, a general guide to the more important values is as follows:


CPUFANIN0 – the CPU (processor) fan – should be a positive value. A value of 0 may be a faulty reading but you should try to visually check if the fan is spinning.

SYSFANIN – the system fan – normally a positive value but not all computers will display a reading.

CPU Temperatures

AMD CPUs typically run hotter than Intel CPUs. Newer CPUs typically run cooler than older designs.

Intel and AMD guidelines for maximum CPU temperatures under full load vary from 75 to 90 degrees depending on the CPU design but, ideally, it should be 30 – 60 degrees max

Hard Drive Temperatures

Vary by hard drive but typically should be 25 – 40 degrees. Over 50 degrees should certainly be considered dangerous.

Graphics Card Temperatures

Vary hugely depending on the card. 40 – 70 degrees is most common.

No Temperatures Shown In HWMonitor?

If HWMonitor does not recognize your components (or their sensors) then it can’t report on their temperatures.

A good alternative to try is Speccy which I reviewed here – although primarily a system info tool to report what components are in a computer, Speccy also reports temperature data for many components.

If you are unable to start Windows then you won’t be able to use either of these tools – but most computers display basic temperature info in the BIOS – often accessed by pressing the Delete or F2 button on startup (or check with your manufacturer to find out which key to use).

Also consider the most obvious physical signs:

  • PC – from the outside of the case, is the power supply too hot to touch? Are any of the metal plates at the back (especially if there is a separate graphics card) too hot to touch?
  • Laptop – does the bottom/side of the laptop feel like it’s going to burn a hole in your trousers?

If the answer to any of these questions is yes, it is likely that the computer is overheating…


HWMonitor is a useful free program to check if a computer is overheating – it can report and track temperatures of key components with compatible sensors.

5 thoughts on “How To Check If A Computer Is Overheating With HWMonitor”

  1. You can check the internet for information about your computer. Then check information about the cpu cooler (fan & heatsink). Then check the forums for a better (higher wattage) cooler. Also check for instructions on how to change the cpu cooler.
    If you use “cpu-z” for the computer information you can ask “Tom’s Hardware forums” for advice. You will need the information about your laptop for anyone to be able to assist you. Ebay has many cpu coolers low priced just be sure it is the one you require before purchasing.
    – – –

  2. Hi, I turned on my computer this morning after it being off all night and it gave me the “cpu is overheating” message… I had barely turned it on, so there’s no way it was actually over heating, right? I’ve noticed no signs like random restarting or anything… and I regularly clean my pc with compressed air. I set my BIO to ignore it and that’s how I got in, but could anything else be causing it? and am I right to ignore it? My brother in-law built this pc for me in January, but him and my sister are getting a divorce now so It’s a bit awkward to ask him anything…

    • Hi, that error message could (in theory) be the result of a faulty motherboard/sensor (misreporting the temp) but the most likely reason is that the CPU is indeed overheating…

      A CPU can overheat within a second of starting up e.g. if the CPU fan is faulty or the heatsink wasn’t put on right and has come loose.

      If it is genuinely overheating and ignored it will likely damage the CPU or the PC will shut down to try and protect itself. Would be a good idea to check the temperatures, heatsink and fan carefully to make sure – or get a tech to look at it

  3. Two comments for this. One, what to do if it is overheating??? Since it should be built to cool itself as it runs, how is anyone to change this problem or resolve it? My laptop overheats even in cool weather so in summer it is a real problem, since it is also my primary working computer. I have not found a cooling solution, from cooling pads to external fans.
    Second, the install for the software tries to change people’s toolbars & search to, automatically checks YES & gives a “fake” accept this agreement to use to install the software dialogue that would make the non-tech user think it was required to install the HWMonitor. Not sure if it had this in it when you recommended it, if so I’d be very upset that you didn’t warn people before download. In any case my comment may help others avoid it if they see it before they click download anyway. You might want to add this to your article to help them get around it too. I hate software that has these often spyware, malware & other dangerous auto-opt-in add ons during installs.

    • Hi Gina, there are no toolbar/search issues in the portable version that I reviewed and recommended. Although Ask is not malware or dangerous, I have updated the article to make others aware of its inclusion if they choose the install version instead.

      A few models of laptop run hot from new (poor design) but generally overheating will be due to either an overworked processor (too many programs running or not enough system RAM) or a build up of dust inside or a drying out of the CPU/heatsink thermal paste.

      Ideally it should be cleaned from the inside – best to find a youtube video of your make/model (or nearest equivalent) showing how to open it up and clean the vents/fans/exhaust of clogged up dust or, if in any doubt, get a tech who can also test if the internal fan(s) are working properly and replace the thermal paste if required

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