script31.ps1

# script31.ps1
$Name = ""
while ($Name.Length -ne 4) {
    Write-Output "Enter user name (4 characters): "
    $Name = Read-Host
    if ($Name.Length -ne 4) {
        Write-Output "User name should be 4 characters length!"
    }
}

$UserName = "UPart3$Name"
$GroupName = "GPart3$Name"

New-LocalUser -Name $UserName -NoPassword
New-LocalGroup -Name $GroupName
Add-LocalGroupMember -Group $GroupName -Member $UserName
Enable-LocalUser -Name $UserName

Pause