Check "Disable Fast Startup" Status

<#
.SYNOPSIS
    Checks whether "Disable Fast Startup" is currently applied.

.DESCRIPTION
    Reads HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager\Power \ HiberbootEnabled and reports its current value,
    or reports that it isn't set (falling back to the Windows default).

.EXAMPLE
    .\Test-DisableFastStartupStatus.ps1
#>

[CmdletBinding()]
param()

$regPath = 'HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager\Power'

$value = Get-ItemProperty -Path $regPath -Name 'HiberbootEnabled' -ErrorAction SilentlyContinue

if ($null -eq $value) {
    Write-Host "'HiberbootEnabled' is not set at $regPath (using the Windows default)." -ForegroundColor Yellow
} else {
    Write-Host "Current value of 'HiberbootEnabled': $($value.'HiberbootEnabled')" -ForegroundColor Green
}