Clear CMOS on the motherboard, the reasons for this and how to do it

by Kelvin
Очистить CMOS на материнской плате

The so-called Clear CMOS has been one of the few things that has survived in consumer computing over the years, and yet there are times when evolution tends to zero. While the procedure is very simple in general terms, in others it seems like we are 20 years in the past, so there are several ways to achieve it. But the important thing that we have to take into account is the reason why it is necessary to do Clear CMOS on the board, as this is a problem in many cases.

Why do we need to do Clear CMOS on board? In what situations?

clr cmos

One of the key points of this procedure is precisely why, motives. Experienced and knowledgeable users have no problem and know the “risks” involved, but novice users should consider certain points before proceeding.


The reasons are important for one main reason: we will leave the motherboard completely standard, from the warehouse, and in many cases this is what is needed and ideal, but in others it is a problem. Therefore, it is important to understand that sometimes this does not need to be done if we have other alternatives for customization.

By executing Clear CMOS, we will return the entire BIOS to standard, but if any specific parameter was affected and we did not remember or write it down, we will lose that parameter and its configuration. This usually does not happen, but on some boards, for example, you need to manually set the boot parameters to tell the board where Windows set.

For an experienced user, this is completely unscientific, but for a noble person it is a whole world. Another of the most commonly used settings is XMP profiles , you must install the RAM at the highest frequency that can be achieved with the standard configuration with the specified recording technology settings.

Another case that is most often lost and which can cause headaches in the future is the SSD configuration, especially M.2 NVMe … In many cases, we have to assign the speed manually in order not to lose performance, for example, due to the fact that the bus is shared with SATA.

Finally, in this section, we could talk about boot options for compatibility with older devices, or CSM (Compatibility Support Module) … Oddly enough, on some Intel platforms with the new generation of AMD, it is necessary to enable support for outdated versions for video cards, because otherwise the image will not be displayed on the monitor, as in the new RX 6000 and in the previous RX 5000.

Is there a uniform and global way to make Clear CMOS?

reset botons + nutrition + clr cmoss

One of the challenges faced by Noble users is precisely how to accomplish this task and achieve its results. Each plate does this differently, but there is one that works effectively for all of them, although the process can be somewhat cumbersome if access is poor.

But before we make it known, we’ll see some of the new methods in case we can keep it global.

Using the button on the back of the motherboard

clear-cmos button

As a rule, modern mid-range and high-end models already have a button on the rear I / O panel, which, after pressing it (more or less seconds, depending on the manufacturer), will return the BIOS / UEFI to its original configuration, reset in each rule.

This button changes in shape and design depending on the model or manufacturer, so we’ll need to see if our plate has one.

Jumpers are still working

Resetear la Bios

Believe it or not, there are motherboards out there that keep assembling the typical jumpers to accomplish this clearing CMOS process. The jumper is located on the plate in different ways, that is, not all of them are in the same place, so the ideal option in order not to waste too much time is to refer to the instruction manual of our model and see the diagram of the plate. to find it easily.

Typically, a jumper will make contact between the two pins in the OFF position, so it will only be necessary to change the jumper so that the remainder and center jumper do this process. It is recommended that before moving the jumper, disconnect the PC from the power supply return button, and in the worst case, disconnect the power cable from the power supply to the wall so that there is no power, after which we will change the site jumper.

After (usually) 10 or 15 seconds (depending on the manufacturer and model), the BIOS will lose its saved state, and we can reset the jumper to its original position and apply power to the source, turn on the PC and enter UEFI to make sure everything is standard.

Remove battery and power, never fail

Cambyar saw CMOS

If we want not to waste time on any of these procedures, the oldest and most archaic remains relevant today and in all models on the market. Simply power off your PC using the rear power supply button, or unplug the power cable directly if this button is not available.

After that, with a flat screwdriver, press on the battery support gasket, between it and the support that it includes, after which it literally pops out of the grip, and we can remove it. In just 15 seconds with no power, no current or battery, the BIOS will lose its configuration and when we put the battery in, the current will return to its original state.

So you decide how to do it, knowing that if something is misconfigured because it is standard, you will have to manually adjust it after clearing the CMOS on board, so maybe some UEFI snapshots or photos will just help if we are not know what we are listening to.