Test For Drives and Log In Event Viewer.ps1

## Event IDs: 1 - Source $EventLogSource created.
## Event IDs: 2 - Drive Config Written To Disk: $driveConfig
## Event IDs: 3 - Pre-Existing Drive Exists: $Drive
## Event IDs: 4 - Pre-Existing Drive does not Exist: $Drive

## Define variables
$EventLogSource = 'Drive Checker'
$DriveConfig = 'C:\Drive.Config'
$CurrentDrives = Get-WmiObject -Class Win32_LogicalDisk | Where-Object {$_.VolumeSerialNumber -ne $null} | Select-Object Name,Description,ProviderName,VolumeSerialNumber

## Create Event Log If Not Exist
if(!([System.Diagnostics.EventLog]::SourceExists($EventLogSource)))
{
    New-EventLog –LogName Application –Source $EventLogSource
    Write-EventLog -LogName Application -Source $EventLogSource -Category 6 -EventId 1 -EntryType Information -Message "Source $EventLogSource created."
}

## Create DriveConfig if it doesn't exist
if(!(Test-Path $DriveConfig))
{
    $drives = Get-WmiObject -Class Win32_LogicalDisk | Where-Object {$_.VolumeSerialNumber -ne $null}
    $drives | Select-Object Name,Description,ProviderName,VolumeSerialNumber | Export-Csv -NoTypeInformation -Path $DriveConfig -Force

    Write-EventLog -LogName Application -Source 'Drive Checker' -Category 2 -EventId 2 -EntryType Information -Message "$DriveConfig written to disk."
}

## Get Contents of Drive Config
$DrivesToSearchThrough = Import-Csv -Path $DriveConfig

## Test for the drives against the Drive Config, write to the event log
foreach($Drive in $DrivesToSearchThrough)
{
  if(!($CurrentDrives.Name.Contains($Drive.Name)))
  {
    Write-EventLog -LogName Application -Source $EventLogSource -Category 2 -EventId 4 -EntryType Error -Message "Drive from configuration file not found: $($Drive.Name)" 
  }
  else
  {
    Write-EventLog -LogName Application -Source $EventLogSource -Category 2 -EventId 3 -EntryType Information -Message "Drive from configuration file found: $($Drive.Name)"
  }
}