if /i "%value%" == "J" (     
  set /p =Ordnername angeben ^(d oder b^):
)

if /i "%value%" == "J" (     
  set /p ="Ordnername angeben (d oder b):"  
)

@echo off
setlocal EnableDelayedExpansion

choice /c JN /m "Sollen die Dateien zuerst erneuert werden"  
if %ErrorLevel% equ 1 (
  choice /c BD /m "Ordnername angeben"  
  if !ErrorLevel! equ 1 (
    REM: Aktion bei B
  )
  if !ErrorLevel! equ 2 (
    REM: Aktion bei D
  )
)

$source = "E:\Quelle1"      
$target = "E:\Ziel1"  

$ErrorActionPreference = "Stop"  
#von Quelle ins Temp kopieren
foreach($file in Get-ChildItem $source -file -filter *.txt -recurse){
   Try{
     $dst = "$target\$($file.Name)"      
     $cnt = 1
     while(Test-Path $dst){
         $dst = "$target\$($file.Basename)_$cnt$($file.Extension)"      
         $cnt++
     }
     $file | Copy-Item -Destination $dst -force -verbose
      if ((Get-FileHash -LiteralPath $file.Fullname).Hash -ne (Get-FileHash -LiteralPath $dst).Hash) {
           Throw "Checksummen stimmen nicht überein '$($file.Fullname)' <=> '$dst'"     
       }else{
           Remove-Item $file.Fullname -force
       }
   }catch{
       write-host $_.Exception.Message -F Red
   }
}

clear
$Computernames = Get-Content "host.txt"  
#$Computernames = Get-ADComputer -Filter * -Searchbase = ... |


$Computernames | ForEach -Parallel {
    $ComputerName = $_

    try {
        #psexec "\\$ComputerName" -h -u larch\administrator -p <pass> -s -d -f -c "C\Users\Administrator\Downloads\inventory\test.ps1" 
       
            }
    catch {
        # ... error
    }
}


Pause

$source = "E:\Quelle1"    
$target = "E:\Ziel1"   
$temp = "E:\Temp"   
#von Quelle ins Temp kopieren

foreach($file in Get-ChildItem $source -file -filter *.txt -recurse){
     $dst = "$target\$($file.Name)"    
     $cnt = 1
     while(Test-Path $dst){
         $dst = "$target\$($file.Basename)_$cnt$($file.Extension)"    
         $cnt++
     }
     $file | Copy-Item -Destination $dst -force -verbose
}
if ((Get-FileHash -LiteralPath $source.FullName).Hash -ne (Get-FileHash -LiteralPath $target.FullName).Hash) {
     Throw "Checksummen stimmen nicht überein"   
         Remove-Item $source\*.txt -force }

Invoke-Command -ComputerName "LA-DATA" -ConfigurationName "Demo" -ScriptBlock {  
  #...
}