Hi Sam,
In order to use a custom action, you can go in the
“Custom Actions” page and add a predefined
Launch attached file custom action with sequence. This type of custom action can execute an application (EXE or DLL) or run a script (VBScript or Java script). Also, the source file will be embedded in the MSI file but will not be deployed at install time with the other application files.
You can also try to add it as a
prerequisite. Here's the
Add Prerequisite article which may be useful to you.
Please let me know if that helped.
Best regards,
Dan