Backup Operating System Info List to JSON

<#
.SYNOPSIS
    Backs up Operating System Info (Win32_OperatingSystem) to a timestamped JSON file.

.DESCRIPTION
    Queries Win32_OperatingSystem via WMI and writes Caption, Version, OSArchitecture, LastBootUpTime, FreePhysicalMemory for every item to a
    JSON file, useful as a point-in-time snapshot for change tracking.

.PARAMETER OutputFolder
    Folder to write the JSON snapshot into. Created if it doesn't exist.
    Defaults to the current directory.

.EXAMPLE
    .\Backup-OperatingSystemListToJson.ps1 -OutputFolder C:\Snapshots
#>

[CmdletBinding()]
param(
    [string]$OutputFolder = '.'
)

if (-not (Test-Path $OutputFolder)) {
    New-Item -ItemType Directory -Path $OutputFolder -Force | Out-Null
}

$items = Get-CimInstance -ClassName Win32_OperatingSystem | Select-Object Caption, Version, OSArchitecture, LastBootUpTime, FreePhysicalMemory
$timestamp = Get-Date -Format 'yyyyMMdd-HHmmss'
$outPath = Join-Path $OutputFolder "operatingsystem-snapshot_$timestamp.json"

$items | ConvertTo-Json -Depth 3 | Out-File -FilePath $outPath -Encoding UTF8

Write-Host "Snapshot of Operating System Info ($($items.Count) items) saved to $outPath" -ForegroundColor Green