Command Line

Installers and uninstallers can run with no window, for scripts, for installing on many PCs, or on a PC without Direct3D 12. The app itself has no command line: it always opens its window.

Everything on this page is taken from the code at version 0.6.0. The README has the same in Automating the installer.

• Use an administrator's PowerShell. Installers and uninstallers always demand administrator rights. From an ordinary PowerShell, Windows refuses to start them, with "The requested operation requires elevation".
• Pipe the output somewhere. Installers are windowed programs. PowerShell only waits for one, shows what it prints, and sets $LASTEXITCODE, if you pipe it, for example to Out-String.
• Any argument at all skips the window. Double-clicking, with no arguments, opens the window. With any argument, an installer runs without one.
• Check the signature yourself. A command-line install prints nothing about a signature. Check the file with Get-AuthenticodeSignature before you run it.

Fabrikam_Data_Sync_installer.exe [--target-root <DIR>] [--dry-run | --apply] [--force]
                                 [--restore-user-data] [--no-restore-license] [--log <FILE>]

With arguments that do not say what to do, such as --force on its own, it prints a short usage note and exits with 0.

The window and the command line put user data in different places by default. The window's User Data box starts ticked, so user data goes to its real folders. On the command line, user data goes under the install location unless you add --restore-user-data. License data is restored by both, unless you untick License or add --no-restore-license.

They also differ on what is already there. Once the window has checked its folder, it replaces a file, registry value, service, task, shortcut, or variable of the same name, as --force does. On the command line without --force, a file it would write that is already there, such as an AppData file with --restore-user-data, stops the install before anything changes.

In order:

1. Room: how much room it needs on each drive, and how much is free.
2. Sets up: how many things it sets up beyond files, then one line for each, as Kind: name: what it does, the same as the window's list. Notes follow, as Note: lines.
3. Reinstall applied. or Reinstall previewed.
4. Changes logged: with a count, then Warnings:, Errors:, and Refused:, each with a count and one line per item. Each warning and error starts with a short code, such as service_account_not_restored.
5. Package hashes valid: and, after an install, Reinstall hashes valid:, each true or false.
6. Install id: the id of the install, which the uninstaller needs.
7. If the install failed: The install failed, so what it changed was put back., then what was undone, what could not be, and what was left.
8. Log: the path of the log.

If it stops before installing anything, it prints error: and why, on the error output, with the log's path if there is one.

Preview, to see what an install would do at a location:

.\Fabrikam_Data_Sync_installer.exe --target-root "C:\Program Files\Fabrikam Data Sync" | Out-String

Install, keep what it printed, and act on the exit code:

$installer = ".\Fabrikam_Data_Sync_installer.exe"
$output = & $installer --target-root "C:\Program Files\Fabrikam Data Sync" --apply | Out-String
$code = $LASTEXITCODE
$output
if ($code -eq 0 -and $output -match 'Install id: (\S+)') {
    "Installed. Install id: $($Matches[1])"
} else {
    Write-Warning "The install did not work (exit code $code). See the output above."
}

To keep the error: line in $output as well, add 2>&1 before the pipe.

Install with the user data going to its real folders, without the license, and with a log of your own:

.\Fabrikam_Data_Sync_installer.exe --target-root "D:\Apps\Fabrikam Data Sync" --apply --restore-user-data --no-restore-license --log "C:\Logs\fabrikam-install.log" | Out-String
$LASTEXITCODE

Without --force, an install stops before changing anything if the location has files in it and no install of this project is on record there, whether or not any would be replaced, and also if a file it would write already exists. The window will not use such a folder at all, and replaces what is in a folder it does use.

With --force, it replaces existing files, registry values, services, tasks, shortcuts, and environment variables. A file it replaces comes back when you uninstall.

Only use it for a folder you know is this app's. A file of the same name is replaced, and another app's service could be running that file. Even with --force:

• services, tasks, and what ties an app into Windows stay another app's;
• outside the install location, no program goes into a folder that was already there without an install on record. A data file there is replaced.

Each install leaves an uninstaller at a fixed place: %ProgramData%\WinAppMigrator\installs\<id>\uninstall.exe. It only ever reads the record in that place.

uninstall.exe --uninstall <ID> [--quiet] [--remove-user-data] [--log <FILE>]

• The installer prints it, as Install id:, when it installs from a command line.
• The app's entry in Settings holds the full command, in the registry values UninstallString and QuietUninstallString. For example, in an administrator's PowerShell:

Get-ItemProperty 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*',
                 'HKLM:\Software\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\*',
                 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*' -ErrorAction SilentlyContinue |
    Where-Object DisplayName -like 'Fabrikam Data Sync*' |
    Select-Object DisplayName, QuietUninstallString

A 32-bit app's entry may be under WOW6432Node, a per-user app's under HKCU:, and the name may carry a version.

• Each install's folder under %ProgramData%\WinAppMigrator\installs is named by its id, starting wam-.

With --quiet: Uninstalling and the app's name, then Undone:, Could not be undone:, Left in place:, and Left behind:, each with a count and one line per item, then Log: and the log's path.

When it does not finish, the entry in Settings stays, so you can run it again.

& "C:\ProgramData\WinAppMigrator\installs\wam-abc123\uninstall.exe" --uninstall wam-abc123 --quiet | Out-String
if ($LASTEXITCODE -ne 0) { Write-Warning "The uninstall did not finish (exit code $LASTEXITCODE)." }

Here wam-abc123 stands for the real id.

If an installer's window cannot open, it shows a message ending: "It can still install without one: run this file from an administrator's command prompt with --apply, and --target-root followed by a folder to choose where."

If an uninstaller's window cannot open, its message gives the exact command, with --quiet, for that install.

Logs are kept in %ProgramData%\WinAppMigrator\logs, which only administrators can read. The last 20 are kept. A preview from the command line starts no log of its own there. Logs hold paths and key names, and never what a registry value, license file, or environment variable holds. See Files it keeps on a PC.

Last changed 2026-11-11. Describes WinAppMigrator as of its latest release, 0.6.0.