This basically deals with the problem when your PC is showing the incorrect time in Windows even after you may have adjusted it various times in settings. The correct time is important for such things as updates (which can be blocked) and various software which will not run with the incorrect time. Naturally, it is also always useful to just know what time it is 😊
So, that is what you must first check. Is the time set correctly in Windows Settings (right-click on the clock in the lower corner of the desktop and click on change date/time).
-check date and time
-check you have the correct time zone for your country
-you can also leave automatic time synch switched on which will check with a server and synch the correct time to the PC. (after a while)
You can also check if the correct time is set in BIOS.
-Turn off PC by holding the power button
-Turn on PC and continuously press ESC until startup menu appears
-Press F10 to enter BIOS
-Set the correct date and time and exit BIOS saving changes
Now let’s quickly take a look at a few scenarios:
New PC wrong time after every reboot:
You have a brand new PC which is showing the wrong time after every reboot. Maybe a few hours off. Newer model notebooks have no CMOS battery (RTC battery) so it is not going to be the failure. I have come across this situation a few times recently and the solution was to update the BIOS of the machine. (It is a good idea to completely update a new PC in Windows settings and HP support assistant with all the necessary reboots in any event)
So to update BIOS you can open HP support assistant which you can find in Start Menu or by clicking on the blue circle icon with the question mark in it in the Task Bar
Here click on updates and see if there is a BIOS or Firmware update available and install. Update everything else while you are at it.
You can also insert your model or product number (how to find it) into product search page (here) and go to the drivers and software section. You should be able to find the latest BIOS available in the list. Download and install.
Dual Boot Linux and Windows
You have created a dual boot situation on your PC with Windows and Linux and the time is not correct in Linux or in Windows.
Linux uses UTC time and Windows local time.
In this situation, you either need to make Linux use local time or Windows use UTC time so that they will both show the correct time
In Windows 64-bit create a QWORD and in Windows 32-bit create a DWORD
Double-click on the new entry and set the value to 1
Wrong time and date at every reboot (CMOS / RTC battery)
The CMOS battery should last for about 5 years or more, so if it is a new PC this most likely is not the problem.
If the time and date are wrong at every reboot (maybe even, always the same incorrect date and time) it could be that you need to replace the CMOS battery (RTC battery). Usually, there will be other problems, such as errors at boot, the might stop at boot and ask you to adjust settings and time (every reboot once not connected to external power) and all BIOS settings will fall back to default each time with various problems that can arise from this.
To replace the CMOS battery in desktop is usually quite easy, you will see the coin battery on the motherboard (CR 2032 battery) which you can remove and replace with a new battery for a couple of $ or less. To open the case of the desktop you can go to the product page of your model and under the heading Manuals, you will find manuals on how to open the case to replace hard drive or RAM.
Look for the CMOS battery on the motherboard and replace it.
Many notebooks also use the same battery or can have different shapes of the battery. Modern notebooks where the main battery is non-removable may not have an RTC battery.
Usually, in notebooks it is more difficult to replace the battery. Sometimes it is accessible under the service door, but many times you will need to remove the bottom or top cover of the notebook to get access to the battery on the motherboard. You can usually find the service manual for the notebook on the product page for your model under the heading Manuals, In the manual search for RTC battery and there will be the steps on how to replace it.
Forcing the correct time
I wrote this article after reading the suggestion by @anthony82 in this thread
Basically, this avoids the underlying problem of what is causing the wrong time by creating a Task in Windows at boot where the PC will connect to a time server and adjust the time/date at every reboot. This will work in most cases but is avoiding the problem and if you have a bad CMOS battery, the time/date will not be the only problem.
It will only work if the PC is connected online at startup.
I hope it helps and please reply if this does not solve your issue.