Clear CMOS Settings
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- เผยแพร่เมื่อ 5 ต.ค. 2024
- In this video from ITFreeTraining, I will look at how to clear the CMOS settings on a computer. When changes are made in the BIOS or UEFI, these settings are stored in the CMOS. This video will look at how to clear these settings which will return the computer back to its factory defaults.
Download the PDF handout: itfreetraining....
BIOS and CMOS
0:19 Before I start, I will first look at how the BIOS and the CMOS work. This will give you a better understanding of what happens when the settings are cleared. In this video, I will only refer to BIOS, but if you have a computer with a UEFI chip on it, the principal is the same and the procedures are also the same.
The BIOS is a small chip on the motherboard. This chip contains a small amount of code and when the computer is first switched on, this code tests the hardware and starts the computer.
The BIOS also contains setup software that allows configuration changes to be made to the computer. These configuration changes need to be stored somewhere, but cannot be stored in the BIOS because it is read only.
In the early days of computing, this configuration was stored in a chip called the CMOS. CMOS stands for complementary metal-oxide semiconductor. Nowadays, motherboards do not have a CMOS chip, but instead the configuration is stored in the South Bridge.
The size of this storage varies, but in modern motherboards it is around 64 kilobytes. The average computer may only require 100 bytes of storage depending on what options you configure. This storage is traditionally volatile, meaning that when the power to the computer is switched off everything in memory will be lost.
Since this data is the configuration for the computer, you need the configuration to be available even if the computer does not have power for long periods. To do this, the motherboard will have a battery installed. This battery keeps the memory powered and thus data will not be lost between reboots.
You may be thinking, why not use flash RAM as it is non-volatile and thus keeps its values between power losses? A lot of modern motherboards use flash RAM and thus do not require power to keep their settings. Even if flash RAM is being used, the settings are still referred to as CMOS because administrators are so used to calling it by that name. If we are making the move to flash RAM, the question arises, do we still need the battery?
The battery is still found on modern motherboards because it is used to power the clock. The clock is referred to as the real time clock or RTC. The battery allows the clock on the motherboard to function even when the computer is not powered. This allows the computer to accurately keep track of the time, including the current date even if the computer is not connected to the power for a long period of time.
Now that we understand how the settings are saved, what happens if you make a change to CMOS on your computer and the computer becomes unbootable? The most common time this occurs is when a password has been configured and no one knows what that password is. When something like this occurs, you need a way of clearing the CMOS settings.
Clearing CMOS
3:13 1_Bullet12_Jumper
To clear the CMOS settings, which will set the motherboard back to factory defaults, there is a jumper on the motherboard. To clear the settings, move the jumper to the second position and start the computer up.
Clearing CMOS
3:25 If you have trouble locating the jumper, refer to the motherboard manual for its location. It is usually located next to the BIOS chip. There will usually be some printed text next to it help you find it. Usually it will have the letters CLRTC which stand for Clear Real Time Clock. Essentially you reset all the settings and also reset the real time clock. If you have a computer that you keep having to set the time and date on, chances are the battery on the motherboard is dead.
I will now have a look at how to reset the CMOS and also have a look at the effect removing the battery will have on the computer.
Demonstration
4:05 First, I will start the computer and press the delete key to enter the setup. Once in the setup, notice that the date is currently set correctly. Once I reset the CMOS setting, we will notice that the time and date will not be correct.
Description to long for TH-cam. Please see the following link for the rest to the description. itfreetraining....
References
“The Official CompTIA A+ Core Study Guide (Exam 220-1001)” Chapter 3 Position 6115 - 6269“CompTIA A+ Certification Exam Guide Tenth Edition” pages 125 - 126
Credits
Trainer: Austin Mason ITFreeTraining.com
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A perfect example of how a detailed informative video should be.
Thanks. Glad you like the video.
You explained each information very clear and understandable. Thank you so much. Thumbs up 👍
Glad it was helpful!
This is so good. Much appreciated.
You're very welcome!
I have a asus motherboard but I followed everything you said and it's working! Thank you.
Great to hear!
unbelievable, this make it clear about CMOS, thank you
You're very welcome!
This is the best video out there,, hands down. Ok, I have 3 long beeps 2 short beeps. I have a cmos reset button on the motherboard. Does this work as the jumpers? I unplugged it, pulled the batter for 5 minutes and pushed the reset button on the motherboard and voila. This is a great video. Liked and subscribed.
Thanks, glad we could help.
I have the same bios as yours but it is stuck on the page where it says phoenix bios . It is stuck at memory testing and the computer is not booting can you help?
wow big help,.....am taking PC fundamental class and instructor dose not really show step by step.........so this video is great need more out there that walk you through a step by step.thanks
Keep it up !
Your channel really helps me so much.
Glad to hear that!
My procedure it critically different than in this video! My ASUS Motherboard manual has me turn off and unplug the power cord before moving the jumper. Wait 5-10 seconds. Move the jumper back, then plug in the PC and turn it on.
It may be different for some motherboard. Hope it worked for you.
new to debugging motherboard codes. I have a 'd3' code on a asus board, im going to try this since it sounds like a great place to start :)
Well done
Cleared 🤝
Thank you so much 👍
Hi, great video. Sorry, I have a quick question: in order to reset the CMOS, do you keep the jumper cable connected to the extreme right side pins or after a while do you reposition them to the left?
It depends on the motherboard. When you put the jumper in the second position and start the computer up, some computer will restart and give you a message the BIOS was reset. Others will reset the BIOS and just give you a black screen and you need to switch the computer off, remove the jumper and start the computer up again. Have a look at your motherboard manual for confirmation.
Clear and concise! Good Job!
Thanks for watching.
Excellent. clear & concise.
Glad it was helpful!
I love you explain things! makes easier for everyone. Thanks a lot for the valuable channel.
Thanks very much.
You're better than Morgan Freeman when he comes to explain something.
Thanks.
Great video! I learnt a lot. 👍
Will this work with Intel NUC Skull Canyon? Intel NUC Mini PC i7-8705G with RX Vega M GL Graphics
My PC failed a BIOS update last night and I'm losing sleep. Lol.
Great video, it takes lots of courage and efforts to make such contents.
Thankyou
Thanks very much and thanks for watching.
Please note that without CMOS battery, when the computer shuts off, all BIOS settings will be returned to factory defaults, leading to the error message every time the computer turns on stating that you have to set date and time.
The exception to this is that modern computer store the settings in flash so does not require power. Thus, only the date and time is affected.
Where is that jumper piece?
It should be there, otherwise maybe it was removed. If it not on the motherboard, you can always buy one or use one for another motherboard.
Will this method clear the admin password in the bios? thank you in advance
Depending on your motherboard the process may be slightly different. But it will clear the admin password.
I already have replaced the battery but it's still the same error.
What is the error? Most likely the settings are in flash and won't change when the battery is removed, or it is an error message relating to hardware.
thank u
You're welcome!
Thanks 👍
Od if I take the main battery out also have to take the CMOS battery out or will the main battery be okay
Taking out the CMOS battery out won't effect the laptop battery. However, if you don't remove the laptop battery it may continue to keep powering the laptop depending on the laptop.
What is there's no jumper, just the 2 pins?
In this case, your motherboard most likely just needs the two pins jumped in order to reset the settings. Refer to your motherboard manual for more information.
My pc turns off automatically and keep restrating; sometimes it shows previous overclocking had failure.
What can i do?
Is the computer just switching off randomly or restarting? It may be the capacitors if it keeps randomly restarting. If it is switching off it may be the power supply.
CMOS reset button do the same thing as the jumper?
This, if your computer has this, the reset CMOS button will achieve the same effect.
Mine what it does, displays :
Error 0211: keyboard not found
Error 0162: Setup data integrity check failure
Error 0175: System Security - Security data corrupted
What is it that must be done? Because I did try your method but still.
Try resetting the BIOS back to defaults and updating it. Have a look at this article.
support.lenovo.com/au/en/solutions/ht081068-system-displays-a-post-error-message-0175-upon-next-system-reboot-after-setting-a-new-bios-password-thinkcentre-m92z
Hey man quick question? I just upgraded from the Ryzen 5 3600 to the 3700x, and everything seems to be fine and working. I click on SYSTEM and it shows I now have the 3700x as my cpu, but when I try to enable All cores and when I go into the Task manager, still says 3700x but under CPU its still showing 6 cores and 12 threads from my 3600? Any ideas as to why this is, and how to fix it? Please Help. And Thanks
Good video, however must I flash a new bios to accomplish the act?
Flashing the BIOS updates the BIOS but keeps all the old settings. Clearing the CMOS will clear all the settings.
@@itfreetraining Thanks for your help and Time!!
thanks bro
Thanks for watching.
Thank you
Thanks for watching.
Why my fbs 1333 mother board CTL CMOS possition in 2-3 pin and got black screen.. When i see your video i think thiers a problem with my pin possition. So i back it into 1-2 and switch it on but no power at all.. And when i back to 2-3 thier a power light and fans but always Black screen..
That is strange. Did you attempt to do a BIOS upgrade that failed? You could try starting the computer up with no-jumper, that should be the same as position 1-2. I would suggest trying changing your video card. Maybe that has something to do with it. Are you getting a single start up beep when the jumper is not in place or in position 1-2?
I think some mainboard need to turn on the computer during clear CMOS，some mainboard does not need to turn on the computer , just need to move the jumper to another position , then wait a moment（In general ，some need to wait 10 seconds ，some need to wait 5 minutes），then move the jumper to original position ， then turn on your computer ， at this time . You have clear the CMOS. If so, please tell me, thank you.
when remove battary CPU full setting reset?
No, it does not reset the CPU.
I found only one
jumper but just 2 legs ??
Some have 2 pins. When this occurs usually it just needs to be shorted to reset the the BIOS. But referred to your manual for more information.
This was a great video. Got a problem though. I have the BIOSTAR A320MH motherboard. A while ago, I accidently increased the CPU clock too high and it wouldn't boot. After placing the jumper on the second and third pins, the settings were reset and the computer worked fine. However, after clearing everything, I tried to put the jumper back onto the first and second pin (which is what BIOSTAR says you should do) and the computer would not boot. Put the jumper cap back to the second and third slot, and the CMOS was cleared, and it booted again. Do you know why this is? The first and second pins are the "normal" ones according to the motherboard label FYI. Weirdly enough though, the picture they use for the overview page has the jumper on the second and third pins.
That is interesting. Some motherboards when they are on certain pins the BIOS will be cleared, however the computer will not start up. I am guessing that for normal operation that particularly motherboard requires the jumper to be in the second position.
my motherboard a320m s2h has 4 pins clr_cmos. how am i gonna short it
Your motherboard is a little confusing. The manual is available from the following link.
download.gigabyte.com/FileList/Manual/mb_manual_ga-a320m-s2h_e_v3.pdf
On page 4 it has the diagram of the motherboard where I can see the four pins you are talking about. These four pins are not all the CMOS pins. The top two you can see the arrow for CI. The bottom two you can see CLR_CMOS. It is easy to miss the arrow for the top two being CI and thus think all four are CMOS pins. If you go to page 19 it explains 15) CI (Chassis Intrusion Header) and 16) CLR_CMOS (Clear CMOS Jumper). So the pins you want are the two closest to the edge of the motherboard.
motherboard gigabyte ga-h110m-h, how about with this motherboard?
This motherboard has one jumper on it. You just need to short this one to clear the CMOS. If you have a look at the motherboard diagram in the manual it will show you where to find it.
download.gigabyte.com/FileList/Manual/mb_manual_ga-h110m-h(ddr3)_e.pdf
if i reset my bios via clear cmos would i have to format windows again or updating bios is enough?
Not sure what you are doing. If you update your BIOS windows should still boot o.k if everything goes fine. If you reset your BIOS, Windows should still boot. However, if there are settings in the BIOS Windows needs to boot it may not. Settings that effect Window are things like hard disk controller set to AHCI, SATA, RAID etc. Also, if you have Bitlocker you will have problems.
@@ITFreeTest omg fastest response ever
Firstly i thank you for your concern
İm at 5 am in my local clock it nearly morning im struggling with a problem like 8 hours. İ dont know anything about pc im a dentist
The problem is i have msi b450m a pro motherboard and 2x gskill 8 gb jipsaw ram
@@ITFreeTest sorry accidently entered
Anyway my set up nearly 1 years old and i just realized my pc looks like having only one 8 gb ram
İn my pc properities it says 8 gb hardware reserved ram
İn dxdiag it says 16 gb
But when i go ctrl alt del go to performance it says 8 gb total
When i check my bios
İt says 2 ram slota are plugged in evety data is correct but it says total memory is 8 gb
İ switched my rams nothing changed
İ tried to use each ram one by one for the slots one by one and turns out my rams are fine but second slot i think its b slot is not working
İf i put 1 memory ram on b slot and left a empty pc dont work dont show any display
@@ITFreeTest i still dont know if my problem hardware originated or not
İ though clearing the cmos data may set up everything back to factory issue
Therefore restore my second ram slot
But i didnt wanna format my pc all over
@@ITFreeTest i already liked the video and subscribed i hope you ll give me some tips .im desperate right now
hi can you help me with a issue on my new build please.before i over clocked cpu i could get into bios easy, now after i over clocked i needed to look at something in bios, i tried almost everything to get in.when i press f2 pc switches on but monitor stays black goes to sleep mode, if i dont touch keys boots up perfect.mb is asrock taichi ultimate
Thinks like fast booting and other settings can make it difficult to get into the setup during boot up. Since your computer runs UEFI, I would boot into Windows. Once in Windows, hold the shift key down and select reset. This will give you a menu that will have an option to boot into UEFI when the computer is restarted. This will allow you to get into the setup. Then you can change some settings to make it easier in the future.
@@itfreetraining tried that did not work
@@itfreetraining just fixed it, was the new dvi to vga adaptor i changed it to from my old pc .boom got into bios, what was happening every time i his f2 monitor switched off pc still on.thanks for reply.i subscribed
@@itfreetraining ok was not the dvi adaptor once i am in oc mode I cant get in to bios,I am finished setting up bios and installed latest bios driver .so I am all good .thanks for the reply.
i won't be able to install kali Linux 😢😢
You should be able to, if you have problems you may need to disable secure boot.
I had a problem unscrewing my laptop. I tried everything but it's small and hard
Damn that bios so old
Which ones are new?
@@ZamaniTheCeo compared to the new motherboards... Lots of changes and better gui.
Outstanding!
Thank you kindly!