download.ps1

$destinationDir = "C:\Users\$env:Username\eBooks\"
$URI = "https://blogs.msdn.microsoft.com/mssmallbiz/2017/07/11/largest-free-microsoft-ebook-giveaway-im-giving-away-millions-of-free-microsoft-ebooks-again-including-windows-10-office-365-office-2016-power-bi-azure-windows-8-1-office-2013-sharepo/"


$HTML = Invoke-WebRequest -Uri $URI
$Elements = $HTML.AllElements
$Parsed = $HTML.ParsedHtml

$table = $Parsed.getElementsByTagName("tbody")[0]
$tr = $table.getElementsByTagName("tr")

Function Remove-InvalidFileNameChars {
  param(
    [Parameter(Mandatory=$true,
      Position=0,
      ValueFromPipeline=$true,
      ValueFromPipelineByPropertyName=$true)]
    [String]$Name
  )

  $invalidChars = [IO.Path]::GetInvalidFileNameChars() -join ''
  $re = "[{0}]" -f [RegEx]::Escape($invalidChars)
  return ($Name -replace $re)
}

ForEach ($row in $tr) {
    # Loop through the rows
    $cells = $row.getElementsByTagName("td")
    if ($cells[0].innerText -ne "Category") {
        $category = $cells[0].innerText.Replace("\", " ").Replace("/"," ") | Remove-InvalidFileNameChars
        $name = $cells[1].innerText.Replace("\", " ").Replace("/"," ") | Remove-InvalidFileNameChars
        $links = $cells[2].getElementsByTagName("a")
        $destination = $destinationDir + $category + "\" + $name + "\"
        New-Item $destination -ItemType Directory
        ForEach ($link in $links) {
            $href = $link.href
            $hdr = Invoke-WebRequest $href -Method Head -TimeoutSec 60
            $title = $hdr.BaseResponse.ResponseUri.Segments[-1] 
            $title = [uri]::UnescapeDataString($title) | Remove-InvalidFileNameChars

            ($href + "  --  " + $title) | Write-Host

            Invoke-WebRequest $href -Outfile ($destination + "\" + $title)
        }
    }
}