Here’s a PowerShell cmdlet I’ve used to run IE 11 in kiosk mode, run as a different user:
$username = ‘domain\username’
$password = ‘password’
$cred = New-Object System.Management.Automation.PSCredential -ArgumentList @($username,(ConvertTo-SecureString -String $password -AsPlainText -Force))
Start-Process -FilePath “c:\Program Files\Internet Explorer\iexplore.exe” -LoadUserProfile -Credential $cred -ArgumentList “-K http://www.cheaphealthyrecipes.info”
The RunAs cmdlet does encrypt the password, but I’ve not found a way to decrypt the password if the script it run as a different user. Consequently, I’ve just ended up converting the PowerShell cmdlet to an exe file to conceal (not encrypt!) the password.