As an extension to my article on how to Audit Server Reboots, I have put forth a small script that might come handy.

I consciously choose implementing WMI rather than inbuilt command lets as there were several Legacy OS’s still in our enterprise and using the command lets had their own share of issues with fetching the data.

Here is what it does,

• Retrieves event logs pertaining to Windows Reboots via WMI between 2 dates provided by user.
• Script runs/retrieves the data using the current logged in user credentials by default.
• Creates 2 Logs, one with a Snapshot of all the restarts, scheduled vs unscheduled reboots and a full report with detailed information.

<# 
    .SYNOPSIS 
       Retrieves event logs pertaining to Windows Reboots via WMI. 
    .DESCRIPTION 
       Retrieves event logs pertaining to Windows Reboots via WMI between 2 dates provided by user.
       Script runs/retrieves the data using the current logged in user credentials by default.
       Creates 2 Logs, one with a Snapshot of all the restarts, scheduled vs unscheduled reboots and a full report with detailed information.
    .EXAMPLE 
       The script needs a file with all the server names placed in a text file "Servers.txt" in the script root and can start executing directly.
       PS > .\Restart_Audit.ps1
 
    .NOTES 
       Author: Murali Palla
       email: contact@muralipalla.com
       Site: http://www.muralipalla.com/ 
       Requires: Powershell 2.0 
 
       Version History 
       1.0.0 - 12/22/2014
        - Initial release 
    #>
$SourceFile = ".\Servers.txt"
if(!(Test-Path $SourceFile)){Write-Host "Unable to find a File $SourceFile with list of Server Names";exit}
$ServerList = (Get-Content .\Servers.txt) 
do {
$Error.Clear()
$result = 0
[bool]$ValidStart = $false
$StartingDay = Read-Host "Enter the Start date in MM/DD/YY Format"
  if ((!([DateTime]::TryParse($StartingDay, [ref]$result))) -or ($Error.Count)) {
        Write-Host "Your date $StartingDay was invalid. Please try again."
        $ValidStart = $False
    }
    else{
        $ValidStart = $True
        [datetime]$StartingDay=$StartingDay
    }

}until($ValidStart -eq $True)

do {
$Error.Clear()
$result = 0
[bool]$ValidEnd = $false
$EndingDay = Read-Host "Enter the End date in MM/DD/YY Format"
   if ((!([DateTime]::TryParse($EndingDay, [ref]$result))) -or ($Error.Count)) {
        Write-Host "Your date $EndingDay was invalid. Please try again."
        $ValidEnd = $False
    }
    else{
        $ValidEnd = $True
        [datetime]$EndingDay=$EndingDay
    }

}until($ValidEnd -eq $True)

$Collection = @()
$Summary=@()
foreach ($Server in $Serverlist) 
{
    Write-Output "Workgin on $Server"
    $RestartCount=0
    $ScheduledRebootCount=0
    $UnscheduledRebootCount=0

    $objEventLog = Get-WmiObject -ComputerName $Server -Class Win32_NTLogEvent -Filter "
        (LogFile='System' and 
        TimeWritten>='$StartingDay' and 
        TimeWritten<='$EndingDay' ) and 
        (EventCode=1076 or EventCode=1074)"
            
    ForEach ( $Event in $objEventLog )
    {
    $EventCode = $Event.EventCode
    $ServerName = $Event.ComputerName
    $RestartCount++        
    [datetime]$TimeGenerated = [management.managementDateTimeConverter]::ToDateTime($Event.TimeGenerated)
        
    if($EventCode -eq 1074){$RebootType = "Scheduled";$ScheduledRebootCount++}elseif($EventCode -eq 1076){$RebootType = "Un-Scheduled";$UnscheduledRebootCount++}
                
    $CollectionObject = New-Object -TypeName psobject
        Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name ServerName -Value $ServerName
        Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name EventCode -Value $EventCode
        Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name RebootType -Value $RebootType    
        Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name TimeGenerated -Value $TimeGenerated
        Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name User -Value $Event.User
        Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name Message -Value $Event.Message
    $Collection += $CollectionObject
    }
    if($RestartCount -eq 0)
    {
        $CollectionObject = New-Object -TypeName psobject
            Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name ServerName -Value $Server
            Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name EventCode -Value "N/A"
            Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name RebootType -Value "N/A"    
            Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name TimeGenerated -Value "N/A"
            Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name User -Value "N/A"
            Add-Member -InputObject $CollectionObject -MemberType NoteProperty -Name Message -Value "N/A"
        $Collection += $CollectionObject
        $SummaryObject=New-Object -TypeName psobject
            Add-Member -InputObject $SummaryObject -MemberType NoteProperty -Name ServerName -Value $Server
            Add-Member -InputObject $SummaryObject -MemberType NoteProperty -Name RestartCount -Value $RestartCount
            Add-Member -InputObject $SummaryObject -MemberType NoteProperty -Name ScheduledReboots -Value $ScheduledRebootCount
            Add-Member -InputObject $SummaryObject -MemberType NoteProperty -Name UnscheduledReboots -Value $UnscheduledRebootCount
        $Summary += $SummaryObject
    }
    else
    {
        $SummaryObject=New-Object -TypeName psobject
            Add-Member -InputObject $SummaryObject -MemberType NoteProperty -Name ServerName -Value $ServerName
            Add-Member -InputObject $SummaryObject -MemberType NoteProperty -Name RestartCount -Value $RestartCount
            Add-Member -InputObject $SummaryObject -MemberType NoteProperty -Name ScheduledReboots -Value $ScheduledRebootCount
            Add-Member -InputObject $SummaryObject -MemberType NoteProperty -Name UnscheduledReboots -Value $UnscheduledRebootCount
        $Summary += $SummaryObject
    }
}
$CurrentDate = Get-Date
$CurrentDate = $CurrentDate.ToString('MM-dd-yyyy_hh-mm-ss')
$Summary | Export-Csv -Path .\"$CurrentDate`_SUmmary.CSV" -NoTypeInformation
$Collection | Export-Csv -Path .\"$CurrentDate`_Detailed_Summary.CSV" -NoTypeInformation
Write-Output "Reports saved to the below mentioned 2 files in the root of the script.
"$CurrentDate`_Detailed_Summary.CSV" 
"$CurrentDate`_SUmmary.CSV""
Write-Output $Summary | Format-Table -AutoSize