update an already existing install

Question

How to update an already existing install of a product with a new install package? Right now when there is an already installed version on my PC, the setup package says that another version was already installed and just exists. So I have to uninstall the old version and install the new one. But I want the new version to upgrade the old version to new version. How do I do that? I know that the product code must match. I think there is something to do with the upgrade code also. Both answers for visual studio setup projects and wix setup projects are welcome, but I think that there is the same principle beyond them all.

Answer 1

No, to make the install package upgrade itself, the ProductCode must be different in each package. UpgradeCode must match.

You should also configure <Upgrade> element or use <MajorUpgrade> in WiX.

For an example, look at Checking for Oldies section in the WiX tutorial:

Answer 2

You need to keep your Upgrade code constant across the whole project.

Also, WIX will consider only Major and Minor version changes.

Check out this site WIX Upgrades