How to run a batch file in the background when a specific program starts

Question

I want to make it such that when a user runs a specific program, such as Firefox, my batch file starts in the background.

I used the code below, but it makes my batch file start instead of Firefox. I don't want that. I want the batch file to listen to programs in the computer and when a certain program starts, the batch file will start in background.

reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\firefox.exe" /v Debugger /d "D:\Desktop\m.bat" /f

How can I accomplish this?

Answer 1

You can use this PowerShell script:

$query = New-Object System.Management.WqlEventQuery ("__InstanceCreationEvent", (New-Object TimeSpan (0, 0, 1)), 'TargetInstance isa "Win32_Process"')
$watcher = New-Object System.Management.ManagementEventWatcher
$watcher.Query = $query
$watcher.Options.Timeout = [System.Management.ManagementOptions]::InfiniteTimeout
$curProc = $null
While ($true) {
    $e = $watcher.WaitForNextEvent().TargetInstance
    If ($e.Name -eq 'firefox.exe' -and ($curProc -eq $null -or $curProc.ExitTime -ne $null)) {
        $curProc = Start-Process 'cmd' -Argument '/c C:\path\to\script.bat' -PassThru -WindowStyle Hidden
    }
}

It uses WMI to watch for the creation of new processes, and if the process belongs to firefox.exe, it launches a hidden command prompt (unless one is already running from a previous Firefox start).

If you want a new run of the batch file to be started every time Firefox launches, use this simpler script:

$query = New-Object System.Management.WqlEventQuery ("__InstanceCreationEvent", (New-Object TimeSpan (0, 0, 1)), 'TargetInstance isa "Win32_Process"')
$watcher = New-Object System.Management.ManagementEventWatcher
$watcher.Query = $query
$watcher.Options.Timeout = [System.Management.ManagementOptions]::InfiniteTimeout
While ($true) {
    $e = $watcher.WaitForNextEvent().TargetInstance
    If ($e.Name -eq 'firefox.exe' ) {
        Start-Process 'cmd' -Argument '/c C:\path\to\script.bat' -WindowStyle Hidden
    }
}

If you don't want the prompt window to be completely hidden, just change -WindowStyle Hidden to -WindowStyle Minimized.

Save your selected PowerShell script as a .ps1 file. To start it at your logon, place a batch file containing this in your startup folder:

powershell -file 'C:\path\to\powershellScript.ps1' -executionpolicy bypass -windowstyle Hidden