Why is the Powershell script not executed all at once, but in parts?

Question

PowerShell

Hello!
There is a Powershell script assigned to the user logon. In the console, it is executed all at once. And if you apply the policy to the user, then in order for it to be fully executed, you need to reboot. Those. one part was executed, rebooted, the second part of the script was executed.
What the script does: 1) Assigns a corporate signature to the user in Outlook 2) Sets it by default and prohibits editing.

SCRIPT

#Custom variables
$CompanyName = 'CraftGroup'
$SigSource = "\\group.com\SysVol\group.com\Scripts\Signatures\$CompanyName"
$ForceSignatureNew = '1' #When the signature are forced the signature are enforced as default signature for new messages the next time the script runs. 0 = no force, 1 = force
$ForceSignatureReplyForward = '1' #When the signature are forced the signature are enforced as default signature for reply/forward messages the next time the script runs. 0 = no force, 1 = force

#Environment variables
$AppData=(Get-Item env:appdata).value
$SigPath = '\Microsoft\Signatures'
$LocalSignaturePath = $AppData+$SigPath
$LocalSignatureFile = $LocalSignaturePath+'\'+$CompanyName+'.htm'
$RemoteSignaturePathFull = $SigSource+'\'+$CompanyName+'.htm'

#Get Active Directory information for current user
$UserName = $env:username
$Filter = "(&(objectCategory=User)(samAccountName=$UserName))"
$Searcher = New-Object System.DirectoryServices.DirectorySearcher
$Searcher.Filter = $Filter
$ADUserPath = $Searcher.FindOne()
$ADUser = $ADUserPath.GetDirectoryEntry()
$ADDisplayName = $ADUser.DisplayName
#$ADEmailAddress = $ADUser.mail
$ADTitle = $ADUser.title
$ADTelePhoneNumber = $ADUser.mobile
#Setting registry information for the current user
$CompanyRegPath = "HKCU:\Software\"+$CompanyName

if (Test-Path $CompanyRegPath)
{}
else
{New-Item -path "HKCU:\Software" -name $CompanyName}

if (Test-Path $CompanyRegPath'\Outlook Signature Settings')
{}
else
{New-Item -path $CompanyRegPath -name "Outlook Signature Settings"}

$SigVersion = (gci $RemoteSignaturePathFull).LastWriteTime #When was the last time the signature was written
$ForcedSignatureNew = (Get-ItemProperty $CompanyRegPath'\Outlook Signature Settings').ForcedSignatureNew
$ForcedSignatureReplyForward = (Get-ItemProperty $CompanyRegPath'\Outlook Signature Settings').ForcedSignatureReplyForward
$SignatureVersion = (Get-ItemProperty $CompanyRegPath'\Outlook Signature Settings').SignatureVersion
Set-ItemProperty $CompanyRegPath'\Outlook Signature Settings' -name SignatureSourceFiles -Value $SigSource
#присваиваем переменные взяв значения из реестра
$TelephoneNumberREG = (Get-ItemProperty $CompanyRegPath'\Outlook Signature Settings').TelephoneNumber
$DisplayNameREG = (Get-ItemProperty $CompanyRegPath'\Outlook Signature Settings').DisplayName
#$EmailAddressREG = (Get-ItemProperty $CompanyRegPath'\Outlook Signature Settings').EmailAddress
$ADTitleREG = (Get-ItemProperty $CompanyRegPath'\Outlook Signature Settings').ADTitle

$SignatureSourceFiles = (Get-ItemProperty $CompanyRegPath'\Outlook Signature Settings').SignatureSourceFiles

$grog = Get-ChildItem $LocalSignaturePath
$FileExists =  Test-Path "$LocalSignatureFile"

#Write-Output $LocalSignaturePath
#Write-Output $LocalSignatureFile
#Write-Output $SignatureSourceFiles
#Write-Output $RemoteSignaturePathFull
#Write-Output $ADTelephoneNumber
#Write-Output $ADDisplayName
#Write-Output $ADTitle
#Write-Output $FileExists
#Write-Output $grog
#Write-Output "----------------------------------"
Get-ChildItem -Path $LocalSignaturePath -Recurse | Remove-Item -Force;
#Write-Output "----------------------------------"

if ($LocalSignatureFile -eq $FileExists) {

    #Write-Output "+++Файл существует!+++"

        if ($SignatureVersion -ne $SigVersion) {
            Get-ChildItem -Path $LocalSignaturePath -Recurse | Remove-Item -Force;
            Copy-Item "$RemoteSignaturePathFull" $LocalSignaturePath -Recurse -Force;
        }

    } else {

        #Write-Output "---Файла нет---"

        #Write-Output "Началось копирование в папку юзера"

        Copy-Item "$RemoteSignaturePathFull" $LocalSignaturePath -Recurse -Force;
}
  #Write-Output $FileExists

  #Write-Output "Пытаемся заменить параметры в файле"
  
    (Get-Content $LocalSignatureFile -Encoding UTF8) -replace "@TelephoneNumber",$ADTelephoneNumber -replace "@DisplayName", $ADDisplayName -replace "@Title", $ADTitle | Set-Content $LocalSignatureFile -Encoding UTF8

  #Stamp registry-values for Outlook Signature Settings if they doesn`t match the initial script variables. Note that these will apply after the second script run when changes are made in the "Custom variables"-section.
if ($ForcedSignatureNew -eq $ForceSignatureNew){}
else
{Set-ItemProperty $CompanyRegPath'\Outlook Signature Settings' -name ForcedSignatureNew -Value $ForceSignatureNew}

if ($ForcedSignatureReplyForward -eq $ForceSignatureReplyForward){}
else
{Set-ItemProperty $CompanyRegPath'\Outlook Signature Settings' -name ForcedSignatureReplyForward -Value $ForceSignatureReplyForward}

if ($SignatureVersion -eq $SigVersion){}
else
{Set-ItemProperty $CompanyRegPath'\Outlook Signature Settings' -name SignatureVersion -Value $SigVersion}

#проверить актуальность тел. номера
if ($TelephoneNumberREG -eq $ADTelePhoneNumber){}
else
{Set-ItemProperty $CompanyRegPath'\Outlook Signature Settings' -name TelephoneNumber -Value $ADTelePhoneNumber}

#проверить актуальность ФИО
if ($DisplayNameREG -eq $ADDisplayName){}
else
{Set-ItemProperty $CompanyRegPath'\Outlook Signature Settings' -name DisplayName -Value $ADDisplayName}

#проверить актуальность должности
if ($ADTitleREG -eq $ADTitle){}
else
{Set-ItemProperty $CompanyRegPath'\Outlook Signature Settings' -name ADTitle -Value $ADTitle}

#Вот до этого места скрипт выполняется в первый раз. Чтобы применилась последующая нужно #перезагрузиться (она как раз отвечает за назначение подписи по умолчанию и запрет редактирования)

#Office 2016
If ((Test-Path HKCU:'\Software\Microsoft\Office\16.0') -and ($ForcedSignatureNew -eq '1')) { 
        New-ItemProperty HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings' -Name 'NewSignature' -Value $CompanyName -PropertyType 'ExpandString' -Force  
        New-ItemProperty HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings' -Name 'ReplySignature' -Value $CompanyName -PropertyType 'ExpandString' -Force 
    
    #Remove-ItemProperty -Path HKCU:\Software\Microsoft\Office\16.0\Common\MailSettings -Name ReplySignature -Force -ErrorAction SilentlyContinue 
        #Remove-ItemProperty -Path HKCU:\Software\Microsoft\Office\16.0\Common\MailSettings -Name NewSignature -Force -ErrorAction SilentlyContinue 
    
    If (Get-ItemProperty -Name 'NewSignature' -Path HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings') {Remove-ItemProperty HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings' -Name 'NewSignature' -Value $CompanyName -PropertyType 'ExpandString' -Force }  
      Else {  
        New-ItemProperty HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings' -Name 'NewSignature' -Value $CompanyName -PropertyType 'ExpandString' -Force  
        #Remove-ItemProperty HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings' -Name 'NewSignature' -Value $CompanyName -PropertyType 'ExpandString' -Force  
      }  
    If (Get-ItemProperty -Name 'ReplySignature' -Path HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings') { Remove-ItemProperty HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings' -Name 'ReplySignature' -Value $CompanyName -PropertyType 'ExpandString' -Force  }  
      Else {  
        
        New-ItemProperty HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings' -Name 'ReplySignature' -Value $CompanyName -PropertyType 'ExpandString' -Force 
        #Remove-ItemProperty HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings' -Name 'ReplySignature' -Value $CompanyName -PropertyType 'ExpandString' -Force 
      }   
} 
If ((Test-Path HKCU:'\Software\Microsoft\Office\15.0') -and ($ForcedSignatureNew -eq '1')) { 
        New-ItemProperty HKCU:'\Software\Microsoft\Office\15.0\Common\MailSettings' -Name 'NewSignature' -Value $CompanyName -PropertyType 'ExpandString' -Force  
        New-ItemProperty HKCU:'\Software\Microsoft\Office\15.0\Common\MailSettings' -Name 'ReplySignature' -Value $CompanyName -PropertyType 'ExpandString' -Force 
    
    #Remove-ItemProperty -Path HKCU:\Software\Microsoft\Office\15.0\Common\MailSettings -Name ReplySignature -Force -ErrorAction SilentlyContinue 
        #Remove-ItemProperty -Path HKCU:\Software\Microsoft\Office\15.0\Common\MailSettings -Name NewSignature -Force -ErrorAction SilentlyContinue 
    
    If (Get-ItemProperty -Name 'NewSignature' -Path HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings') {Remove-ItemProperty HKCU:'\Software\Microsoft\Office\15.0\Common\MailSettings' -Name 'NewSignature' -Value $CompanyName -PropertyType 'ExpandString' -Force }  
      Else {  
        New-ItemProperty HKCU:'\Software\Microsoft\Office\15.0\Common\MailSettings' -Name 'NewSignature' -Value $CompanyName -PropertyType 'ExpandString' -Force  
        #Remove-ItemProperty HKCU:'\Software\Microsoft\Office\15.0\Common\MailSettings' -Name 'NewSignature' -Value $CompanyName -PropertyType 'ExpandString' -Force  
      }  
    If (Get-ItemProperty -Name 'ReplySignature' -Path HKCU:'\Software\Microsoft\Office\16.0\Common\MailSettings') { Remove-ItemProperty HKCU:'\Software\Microsoft\Office\15.0\Common\MailSettings' -Name 'ReplySignature' -Value $CompanyName -PropertyType 'ExpandString' -Force}  
      Else {  
        New-ItemProperty HKCU:'\Software\Microsoft\Office\15.0\Common\MailSettings' -Name 'ReplySignature' -Value $CompanyName -PropertyType 'ExpandString' -Force 
        #Remove-ItemProperty HKCU:'\Software\Microsoft\Office\15.0\Common\MailSettings' -Name 'ReplySignature' -Value $CompanyName -PropertyType 'ExpandString' -Force 
      }  
}

Answer 1

Perhaps the script is executed completely, but the changes that it writes to the registry are applied only at the next login of the user? if so, how to get around it is difficult to say. although... you can try to set the signature through Exchange EWS, but I don't know if it's possible to disable it there...
insert something into the second part of the script that will create an empty file somewhere and see if the file is created during the first run through gpo.
set-content c:\test\test.file -force