Leave Inno Setup DefaultDirName empty or with message "choose install directory"

Question

I made a plugin for 3ds Max and I need two things:

• A message "Choose your 3ds Max root" in the path field in place of "c:... or d:...".
• I also need that the Next button can't be clicked, if the user didn't choose the path manually with the Browse button.

Thanks much.

Answer 1

• Clear the DirEdit in InitializeWizard event function. You probably want to clear it on first install only, not on re-install/upgrade. Inno Setup itself will not allow user to proceed, unless user selects the path.
• You can change the messages on the "Select Destination Location" in the [Messages] section. Change entries like WizardSelectDir, SelectDirDesc, SelectDirLabel3 and SelectDirBrowseLabel.

[Messages]
WizardSelectDir=Choose install directory

[Code]

procedure InitializeWizard();
begin
  if not IsUpgrade then
  begin
    WizardForm.DirEdit.Text := '';
  end;
end;

For IsUpgrade function, see for example Inno Setup: How to overwrite on install but not on change?

---

Or you can create a completely new custom page:
How to ask the user to specify a folder name (using Inno Setup)?

(and hide the standard one?)

Answer 2

Autodesk 3ds Max stores its installation directory in the Windows Registry. You can set your Inno Setup installer to check that registry entry and use it as a default.

Here's a link to the 3ds Max SDK Programmer's Guide: 3ds Max Install Directory Registry Key.