How to change Windows 10 Lock screen time format?

My Windows 10's time format is 24 hour clock, this includes the taskbar but the lock screen is still 12 hour clock format. How do I change the format of my time in lockscreen?

Same here; I was able to get the lock screen to show HH:MM via my personal account with admin privileges, no hidden admin account needed. This is how:

1. Press Win+R, type intl.cpl and press Enter (this will open "Region" settings)

2. Set your "Short Time" & "Long Time" formats in the window that comes up, then click "Apply."

3. Select the "Administrative" tab at the top, then click the "Copy settings..." button.

4. In the subsequent window, check the box for "Welcome screen and system accounts."

5. Click the "OK" button and lock the PC with Win+L to test it.

I've figured out a better answer than hacking the registry... Thanks to zppinto for putting me on the right track. The problem remained that the time format was still US when no user is logged in.

First activate the hidden administrator user account:

1. Run the Command Prompt as administrator
2. Type in net user to see all the user accounts
3. Type in net user administrator /active:yes to activate the hidden administrator user account
4. Type in net user administrator * to give the administrator user a password - always a good idea

5. Press Ctrl+Alt+Del to Switch users (or logout and log into Administrator account.

   In the administrator account:

   • Open the control panel and click on Change date, time or number format

     

   • Change the Format: on the Formats tab and click on Additional Settings... button (Note: you may want to do language thing here as well, in order to copy it over to the Welcome Screen, etc)

     

   • Click on Time tab and make sure the correct time format is being used (also the date format, etc)

     

   • Back on the Region dialogue box click on the Administrative tab and click on Copy settings... button

     

   • Tick the Welcome screen and system accounts and New user accounts check box to copy the settings to all the Welcome Screen

     

     

Note: my settings took a long time to copy over; thus be a little patient - as the doctor said to the dwarf

Have you tried to:

• Go to "Settings" -> "Language and Time" -> and on "format" -> "change date and time formats"?
• Or go to "Control Panel" -> "clock, language and region" -> "change date formats, time or number" and then change the format? You can also have look at "Additional settings" on that window to see if everything is formatted as expected.

If none of that works, I think only solution will be editing the windows registry. There are some tutorials for Windows 8. I think it will be compatible with Windows 10 too.

PowerShell method:

New-PSDrive -Name HKU -PSProvider Registry -Root HKEY_USERS | Out-Null 
$internationalPaths = @("HKU:\.DEFAULT\Control Panel\International","HKCU:\Control Panel\International")
$hourFormat = "h"
IF($TimeFormat -eq '24h')
{
    $hourFormat = "H"
}       
FOREACH ($path in $internationalPaths)
{
    IF((Get-ItemProperty $path).'sTimeFormat')
    {
        #Windows 10 default time format h:mm:ss tt
        Set-ItemProperty -Path $path -Name "sTimeFormat" -Value "$hourFormat`:mm:ss tt"
    }
    IF((Get-ItemProperty $path).'sShortTime')
    {
        #Windows 10 default time format h:mm tt
        Set-ItemProperty -Path $path -Name "sShortTime" -Value "$hourFormat`:mm tt"
    }
}

More details How to change Windows 10 Lock screen time format by PowerShell