Do we “have” to use MsiExec to install a Wix patch?

Question

We normally install Wix patches (xxx.msp) by double-clicking them. But I see at various places over the internet that we should use the MsiExec utility. For eg msiexec /update patch.msp REINSTALL=ALL

Is there any downside in not using the MsiExec utility?

Answer 1

No, there's no downside. Effectively, double-clicking runs msiexec /p patch.msp .

If your patch updates only the versioned files, EXE and DLL, and work correctly without adding REINSTALL=ALL , then it's great!

The point of using msiexec explicitly is to add REINSTALL=ALL property. It make the installer to re-install all the files. This is usually added to fix the problems where some files do not get updated when the patch is installed directly by double-clicking.