Backup Windows Event Logs

## Will RunAs Administrator if not already elevated - needed for the Security Event Log
If (-NOT ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator")) {
$arguments = "& '" + $myinvocation.mycommand.definition + "'"
Start-Process powershell -Verb runAs -ArgumentList $arguments
Break
}

$date = (get-date -uformat %Y%m%d) + "_" + (get-date -uformat %H%M)
$backuploc = $env:USERPROFILE + '\Documents\EventLogBkps'
$CurrentEventLogs = Get-EventLog -List | select Log
$EventLogList = 'Application','Security','System','Some Custom Log Name'

if (!(Test-Path $backuploc)) { md $backuploc | Out-Null}

foreach ($logitem in $EventLogList) {
    if ($CurrentEventLogs.Log -contains $logitem) {
        wevtutil epl $logitem "$backuploc\$($logitem)_eventlog_($date).evtx"
        $file = Get-ChildItem "$backuploc\$($logitem)_eventlog_($date).evtx"
        Write-Host 'Created: ' -ForegroundColor Green -NoNewline
        Write-Host '$backuploc\$($logitem)_eventlog_($date).evtx' -NoNewline -ForegroundColor White
        Write-Host ' File size: ' -NoNewline -ForegroundColor Yellow
        Write-Host $file.length -ForegroundColor White
    }
}

Write-Host ""

$title = "Clear Logs"
$message = "Do you want to clear all of the primary Event Logs?"
$yes = New-Object System.Management.Automation.Host.ChoiceDescription "&Yes", "Clears event entries in each Event Log."
$no = New-Object System.Management.Automation.Host.ChoiceDescription "&No", "Doesn't clear any entries from Event Logs."
$options = [System.Management.Automation.Host.ChoiceDescription[]]($yes, $no)
$result = $host.ui.PromptForChoice($title, $message, $options, 0)
switch ($result)
    {
        0 {
            Write-Host ""
            foreach ($logtoclear in $EventLogList) {
                if ($CurrentEventLogs.Log -contains $logtoclear) {
                    clear-eventlog -log $logtoclear
                    Write-Host "$logtoclear" -ForegroundColor Green -NoNewline
                    Write-Host " has been cleared." -ForegroundColor White
                }
            }
        }
    }