Temporarily change displayName in Minecraft Launcher profile

link.txt

1. Save the script as the name is defined. (If you place the script on the desktop, you will not have to change link string.)

2. Create a shortcut link and apply the following string (substitute the appropriate paths where necessary).

%WINDIR%\System32\WindowsPowerShell\v1.0\powershell.exe -STA -Command "&{$Module = [IO.File]::ReadAllText([Environment]::GetFolderPath("""Desktop""")+"""\Minecraft_Launcher.ps1""");Invoke-Expression $Module}"

Minecraft_Launcher.ps1

$MCNewDisplayName = Read-Host -Prompt 'Enter the displayName you want to use with Minecraft'
$MCLauncherPath = "${env:APPDATA}\.minecraft\launcher_profiles.json"
function Out-MCLauncherProfiles ([string]$displayName)
{
    $MCProfiles.authenticationDatabase.$MCUser.displayName = $displayName
    $MCProfiles | ConvertTo-Json | Out-File $MCLauncherPath -Encoding ascii   
}
function Start-MCLauncher
{
    Start-Process ${env:ProgramFiles(x86)}\Minecraft\MinecraftLauncher.exe -Wait True
}

Write-Host "`n`nAfter Minecraft Launcher starts and fully authenticates, close it."
Write-Host "Starting Minecraft Launcher for initial authentication..."
Start-MCLauncher

Write-Host "Changing Minecraft displayName to '$MCNewDisplayName'..."
$MCProfiles = (Get-Content -Raw -Path $MCLauncherPath | ConvertFrom-Json)
$MCUser = (Select-Object -InputObject $MCProfiles.authenticationDatabase | Get-Member)[-1].Name
$MCOldDisplayName = Select-Object -InputObject $MCProfiles.authenticationDatabase.$MCUser.displayName
Out-MCLauncherProfiles $MCNewDisplayName

Write-Host "Starting Minecraft Launcher with new displayName..."
Start-MCLauncher

Write-Host "Restoring original Minecraft displayName to '$MCOldDisplayName'..."
Out-MCLauncherProfiles $MCOldDisplayName