Download files from a SharePoint library based on conditions

Question

Hello,
I'm currently using a PowerShell script to download all the files from a SharePoint document library. The script works like a charm! I am now adding a new column to this document library which has the Yes/No choice and Yes is the default. I want the script
to only download the items whose choice is Yes and then change the choice to No. Any advice?
Below is the script I am currently using.
######################## Start Variables ########################
Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue 
$destination = "C:\Temp\scripts\msg"
$webUrl = "http://sp13test.sharepoint.com/"
$listUrl = "http://sp13test.sharepoint.com/Docs/"
$web = Get-SPWeb -Identity $webUrl
$list = $web.GetList($listUrl)
function ProcessFolder {
    param($folderUrl)
    $folder = $web.GetFolder($folderUrl)
foreach ($file in $folder.Files) {
        #Ensure destination directory
#        $destinationfolder = $destination + "/" + $folder.Url 
        $destinationfolder = $destination
        if (!(Test-Path -path $destinationfolder))
            $dest = New-Item $destinationfolder -type directory
        #Download file
        $binary = $file.OpenBinary()
        $stream = New-Object System.IO.FileStream($destinationfolder + "/" + $file.Name), Create
        $writer = New-Object System.IO.BinaryWriter($stream)
        $writer.write($binary)
        $writer.Close()
#Download root files
ProcessFolder($list.RootFolder.Url)
#Download files in folders
foreach ($folder in $list.Folders) {
    ProcessFolder($folder.Url)

Answer 1

Hi NSUT,
Thank you for the script and it almost works 100%. I currently have 7 documents of which only 6 download. The 'Downloaded' column of all 6 changes to 'Yes'. For some reason one column will not update and its document will not download. I am also get he below
error.
Here's my script
######################## Start Variables ########################
Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
$destination = "D:\Temp\Scripts\msg"
$webUrl = "http://sp13test.sharepoint.com/"$listUrl =
http://sp13test.sharepoint.com/Docs/
$web = Get-SPWeb -Identity $webUrl
$list = $web.GetList($listUrl)
#Write-host $list
function ProcessFolder {
    param($folderUrl)
    $folder = $web.GetFolder($folderUrl)
  foreach ($file in $folder.Files) {
 $item = $file.Item
        #Ensure destination directory
        $destinationfolder = $destination
        if (!(Test-Path -path $destinationfolder))
            $dest = New-Item $destinationfolder -type directory
 if ($item["Downloaded"] -eq "No") {
        #Download file
        $binary = $file.OpenBinary()
        $stream = New-Object System.IO.FileStream($destinationfolder + "/" + $file.Name), Create
        $writer = New-Object System.IO.BinaryWriter($stream)
        $writer.write($binary)
        $writer.Close()
 $item["Downloaded"] = "Yes"
 $item.Update();
#Download root files
ProcessFolder($list.RootFolder.Url)
#Download files in folders
foreach ($folder in $list.Folders) {
    ProcessFolder($folder.Url)