Understanding Vital attribute in Windows Installer File Table

Suppose you have an MSI that's trying to add or replace file Foo.bar, and that operation fails. If Foo.bar is marked as vital (with msidbFileAttributesVital) in the File table of the MSI, then the installation will roll back. If the file is not vital, then the user is prompted and allowed to decide if the error should be ignored or if the installation should be rolled back.

What if the opera开发者_JAVA技巧tion fails and the installer is running in silent mode (/qn)? The user cannot be prompted.

It appears (from an MSI log I have) that the installation rolls back, even though the file is not vital. Is there some way to have a silent install proceed in this case?

From my knowledge silent installations always rollback if an error is encountered, no matter what flags and settings you use. This prevents broken installations (for example missing files).

In your case a solution is to use basic UI to prompt the user. Another solution is to use a non-MSI installer which can ignore installation errors.