Is MsiOpenProduct the correct way to read properties from an installed product?

Question

Given an MSI product code I want to get the upgrade code (among other properties) from an already installed product. I have tried this by calling the MsiOpenProduct method,

Answer 1

MsiOpenProduct should be fine So long as you don't run any sequences or actions, it won't do anything. If you want to silence the dialog, you can with careful use of either MsiSetInternalUI() or MsiSetExternalUI().

Another approach you can take, as long as the ProductCode and UpgradeCode are safely static (i.e. as long as they aren't changed by transforms), is to locate the database using MsiGetProductInfo() and call MsiOpenDatabase() on that. The difference is that MsiOpenProduct() (or similarly MsiOpenPackage) applies the transforms that were used at installation time and prepares a session, whereas MsiOpenDatabase() does neither.