Due to a Windows update distributed by Microsoft overnight on August 12, 2026, Auto Start mode with the SiteKiosk user no longer works correctly.
Cause
The issue is caused by the permission restrictions applied by SiteKiosk to the SiteKiosk user account. These restrictions prevent the Windows update KB5121003 from completing all required steps correctly and fully for the affected user account. As a result, NTUSER.DAT cannot be loaded and Auto Start is blocked.
Temporary workaround (first hotfix)
Important: This hotfix must be applied again after every new installation of SiteKiosk.
As a temporary workaround, in addition to uninstalling the Windows update KB5121003, we recommend running the following PowerShell script on an affected computer in a PowerShell session with administrative privileges.
This script provides an initial hotfix. Our development team is working on a final solution in parallel, and we will provide further information as soon as it becomes available.
Please make sure that the SiteKiosk user is completely logged off before running the script.
Procedure for SiteKiosk Online
With SiteKiosk Online, the workaround can be executed remotely, for example via the Recovery Shell of an affected client:
Monitoring > [Client] > Administration > Recovery Shell
Procedure for SiteKiosk Classic Windows
With SiteKiosk Classic Windows, the script must be executed locally using an administrator account:
1. First, unlock the keyboard lock. Instructions: Unlocking the keyboard lock
2. Then log in to the system using an administrator account.
3. Start PowerShell or PowerShell ISE with administrative privileges and run the script.
PowerShell script
# PowerShell Script
$profilePath = 'C:\Users\SiteKiosk'
$account = "$env:COMPUTERNAME\SiteKiosk"
$files = @(
Get-ChildItem $profilePath -Force -File |
Where-Object Name -Like 'NTUSER*'
Get-ChildItem "$profilePath\AppData\Local\Microsoft\Windows" -Force -File |
Where-Object Name -Like 'UsrClass.dat*'
)
foreach ($file in $files) {
& icacls.exe $file.FullName /inheritance:d
& icacls.exe $file.FullName /remove:d $account
& icacls.exe $file.FullName /grant:r "${account}:(F)"
}
Then restart the computer:
#PowerShell Befehl Restart-Computer -Force
Contact
If you have any further questions, please contact our support team at +1 (800) 916-7422 or support-america@sitekiosk.com.