Helper function to set the taskbar icon size

Set-TaskbarFontSize.ps1

function Set-TaskbarIconSize {
    # Sets the windows 11 task bar icon size. Default value is medium.
    [CmdletBinding()]
    param(
        [validateset("small", "medium", "large")]
        [string]$Size = "medium"
    )
    $sizeChart = @{
        "small"  = 0
        "medium" = 1
        "large"  = 2
    }
    try {
        Set-ItemProperty -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\' -Name 'TaskbarSi' -Value $sizeChart[$Size]
        Write-Warning -Message "Taskbar icon set to $Size, please reboot to take effect."
    } catch {
        $PSItem
    }
}