[void][System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint")
#For MOSS 2007 compatibility
Function global:Get-SPWeb($url)
{
  $site= New-Object Microsoft.SharePoint.SPSite($url)
        if($site -ne $null)
            {
               $web=$site.OpenWeb()
            }
    return $web
}
#Site URL and List Name variables
$WebURL = "https://SharePoint"
$LibraryName = "REPORT"  #This can be list or document library, if list has multiple attachements it will download all - Note: This PS will create a folder with list Item ID.
#Local folder to which attachments to be downloaded
$DownloadPath = "E:\Admin\reports"    
#Get the web
$Web = Get-SPWeb $WebURL
#Get the Library
$List = $Web.Lists[$LibraryName]   
    #Loop through each List item
    foreach ($ListItem in $List.Items)
     {
       #Set path to save attachment
       $DestinationFolder = $DownloadPath + "\" + $ListItem.ID         
       #Check if folder exists already. If not, create the folder
         if (!(Test-Path -path $DestinationFolder))
            {
                New-Item $DestinationFolder -type directory
            }
          #Get all attachments
          $AttachmentsColl = $ListItem.Attachments
          #Loop through each attachment
          foreach ($Attachment in $AttachmentsColl)
               {
                 #Get the attachment File
                 $file = $web.GetFile($listItem.Attachments.UrlPrefix + $Attachment)
                 $bytes = $file.OpenBinary()               
                 #Save the attachment as a file
                 $FilePath = $DestinationFolder + " \" + $Attachment
                 $fs = new-object System.IO.FileStream($FilePath, "OpenOrCreate")
                 $fs.Write($bytes, 0 , $bytes.Length)
                 $fs.Close()
                }
    }
