Bios is setting the wrong time for win11

[doobre1]

Before I start please NOTE that I updated the bios to v3 recently, but I can't be sure that the problem started after that action.

When I start the PC into win11 ( i have dual boot win11 pro and win11 iot) the time is always -12hrs behind the correct time. I set the correct time in the bios (many times) reboot and it retains the correct time until it boots into win11 (either version). Then it will show the -12hrs time for a split second on the blue swirly splash screen then automatically shows the correct time. 

However after a reboot anytime later, the incorrect time (-12hrs) will show again, on both the splash screen and inside win11.

I have set the correct time and formatting for the time/date display many many times in both windows, and corrected the bios time so many times.

I have restored the factory settings for the bios through the inbuilt option! in v3

I see an option to go-back to 2.9!!

Seems to me like the bios is not talking to the OS correctly or something??!!!

cheers CD

[idj_779]

Hi doobre1,

Welcome to the HP Community! I am a new volunteer here participating in the HP Solve-a-thon, and I can definitely help you solve this time-traveling glitch.

The good news is that your BIOS is not broken, and the v3 update didn't necessarily break your system. What you are experiencing is a classic "Real-Time Clock (RTC) Desync," which is incredibly common in dual-boot setups.

Here is exactly what is happening: By default, Windows expects the motherboard's hardware clock (your BIOS time) to run in Local Time. However, because you are dual-booting two different operating systems (Win11 Pro and Win11 IoT), they are fighting over how to interpret that hardware clock. When you boot into one, it attempts to sync the time and adjust the BIOS. When you reboot into the other, it reads that adjusted BIOS time, applies your time zone offset again (or misinterprets a 12h/24h format), and shifts your clock by exactly 12 hours. The "split second" correction you see on the splash screen is Windows quickly pinging a web time server and temporarily correcting the display.

To permanently stop the two operating systems from fighting over the BIOS clock, we need to force both of them to treat the hardware clock as UTC (Coordinated Universal Time).

Here is the quick registry fix. You must do this on BOTH your Windows 11 Pro and Windows 11 IoT installations:

1. Click the Start button, type regedit, and hit Enter to open the Registry Editor as an Administrator.

2. Navigate to this exact folder path in the left sidebar: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation

3. Right-click on the TimeZoneInformation folder, select New, and click DWORD (32-bit) Value.

4. Name the new value exactly this: RealTimeIsUniversal

5. Double-click RealTimeIsUniversal, change the "Value data" to 1, and click OK.

6. Restart your PC and boot into your other Windows 11 installation. Repeat steps 1 through 5.

7. Reboot your PC one last time and enter your BIOS (F10). Set the time to UTC time (not your local time).

Save and exit. From now on, your BIOS will strictly tick away in UTC, and both versions of Windows will simply apply your local time zone offset to it. The 12-hour shifts will stop completely!

Thank you for being a part of the HP Community! I am an independent tech enthusiast and volunteer participating in the HP Solve-a-thon, not an HP employee.

If my steps helped you out, please click the Thumbs Up/Yes button below. If this completely resolved your issue, please click Accept as Solution so other users can easily find the answer!