Fix Windows VBS launcher Python detection

launchers/windows/Start Local RLM Cowork.vbs

@@ -1,24 +1,77 @@
 Option Explicit
 
-Dim shell, fso, scriptDir, repoDir, launcher, command, candidate, pythonw
+Dim shell, fso, scriptDir, repoDir, launcher, command, pythonCommand
 Set shell = CreateObject("WScript.Shell")
 Set fso = CreateObject("Scripting.FileSystemObject")
+
 scriptDir = fso.GetParentFolderName(WScript.ScriptFullName)
 repoDir = fso.GetParentFolderName(fso.GetParentFolderName(scriptDir))
 launcher = fso.BuildPath(repoDir, "launchers\launcher.pyw")
 
-pythonw = ""
-For Each candidate In Array("pyw.exe -3.11", "pyw.exe -3", "pythonw.exe")
-    If shell.Run("cmd /c """ & Split(candidate, " ")(0) & """ --version", 0, True) = 0 Then
-        pythonw = candidate
-        Exit For
-    End If
-Next
+If Not fso.FileExists(launcher) Then
+    MsgBox "The graphical launcher could not be found:" & vbCrLf & launcher & vbCrLf & vbCrLf & _
+        "Extract the complete Windows bundle before starting it. Do not run the VBS file from inside the ZIP archive.", _
+        16, "Local RLM Cowork"
+    WScript.Quit 1
+End If
 
-If pythonw = "" Then
-    MsgBox "Python 3.11 or newer was not found. Install Python from python.org and enable the Python launcher, then double-click this file again.", 16, "Local RLM Cowork"
+pythonCommand = FindPythonCommand(shell, fso)
+If pythonCommand = "" Then
+    MsgBox "Python 3.11 or newer was not found." & vbCrLf & vbCrLf & _
+        "Install 64-bit Python from python.org. On the first installer screen, enable 'Add python.exe to PATH' and install the Python launcher." & vbCrLf & vbCrLf & _
+        "Then double-click this launcher again.", 16, "Local RLM Cowork"
     WScript.Quit 1
 End If
 
-command = pythonw & " """ & launcher & """"
+command = pythonCommand & " """ & launcher & """"
 shell.Run command, 0, False
+
+Function FindPythonCommand(shellObject, fileSystem)
+    Dim localAppData, programFiles, programFilesX86, candidates, candidate
+
+    localAppData = shellObject.ExpandEnvironmentStrings("%LocalAppData%")
+    programFiles = shellObject.ExpandEnvironmentStrings("%ProgramFiles%")
+    programFilesX86 = shellObject.ExpandEnvironmentStrings("%ProgramFiles(x86)%")
+
+    candidates = Array( _
+        "py.exe -3.13", _
+        "py.exe -3.12", _
+        "py.exe -3.11", _
+        Quote(fileSystem.BuildPath(localAppData, "Programs\Python\Python313\pythonw.exe")), _
+        Quote(fileSystem.BuildPath(localAppData, "Programs\Python\Python312\pythonw.exe")), _
+        Quote(fileSystem.BuildPath(localAppData, "Programs\Python\Python311\pythonw.exe")), _
+        Quote(fileSystem.BuildPath(programFiles, "Python313\pythonw.exe")), _
+        Quote(fileSystem.BuildPath(programFiles, "Python312\pythonw.exe")), _
+        Quote(fileSystem.BuildPath(programFiles, "Python311\pythonw.exe")), _
+        Quote(fileSystem.BuildPath(programFilesX86, "Python313\pythonw.exe")), _
+        Quote(fileSystem.BuildPath(programFilesX86, "Python312\pythonw.exe")), _
+        Quote(fileSystem.BuildPath(programFilesX86, "Python311\pythonw.exe")), _
+        "pythonw.exe" _
+    )
+
+    For Each candidate In candidates
+        If CommandWorks(shellObject, CStr(candidate)) Then
+            FindPythonCommand = CStr(candidate)
+            Exit Function
+        End If
+    Next
+
+    FindPythonCommand = ""
+End Function
+
+Function CommandWorks(shellObject, candidateCommand)
+    Dim exitCode
+    On Error Resume Next
+    exitCode = shellObject.Run(candidateCommand & " --version", 0, True)
+    If Err.Number <> 0 Then
+        Err.Clear
+        CommandWorks = False
+    Else
+        CommandWorks = (exitCode = 0)
+    End If
+    On Error GoTo 0
+End Function
+
+Function Quote(value)
+    Quote = """" & value & """"
+End Function