Files in Use and Restart manager are two big features of Windows Installer 4. These features provide excellent support to MSI packagers when customizing an application which needs a restart for optimal functionality.

Files in Use:

Files-In-Use functionality is among the countless services that Windows Installer exposes for setup authors to leverage for their application install/maintenance. This functionality lets setup authors display the processes that hold on to files that would be updated by this install. The user would want to shut those processes before continuing with the install to ensure that the install wouldn't require a reboot.

The current Files-In-Use mechanism involves enumeration of the HKEY_PERFORMANCE_DATA key using registry API for information on processes and the PE images that they have held in-use. This works well in scenarios where the process holding the file in use has a visible window that the user can shut down.

These...

Software packages should not automatically repair data (local- or server-based data) on launch. Such an automatic repair could overwrite data changes made by the user. Therefore, components in the MSI that include data files (e.g. Access MDBs) will not contain a key path (thus disabling self-repair), even if this breaks the Windows logo.

The Self-repair (Source Resiliency) process will be reserved to repairing locally installed application executables, registry keys, shortcuts and system files. The package will never be able to repair to a server path (since the application is Run from Source and it is read-only), and under no circumstance should the package repair Data (User or Shared) even if the data resides locally.

In order to support roaming users or more specifically, multiple users using the same application on the same workstation, user data needs to be installed for each user using the application on the workstation.

In order to do this, a HKCU key...

A corrupt file will not trigger Windows Installer to perform a self-repair. This is because the Windows Installer checks only for file existence when checking a component that uses a file for its keypath. Read on to learn more.

Although a corrupted file may not function properly, as long as Windows Installer can verify that the file exists at that location a self-repair will not be triggered. However, if another missing keypath causes a self-repair the corrupted file will be replaced with a functioning copy from the installation source if the file is in the same feature as the component with the missing keypath.

Corrupted files can be repaired by performing a manual repair of the .MSI using the maintenance dialog or by running the MSI via command line with the switch /focmus. Additionally, the following information must be true for the repair to correct the corrupt file:

1. The file must have a internally provided checksum provided. This is...

We all know that there are big Software Delivery packages in the world. We also know that sometimes network infrastructure lets us down. So what do you do when you have this monster of a software delivery package to get to clients, and the network hiccups in the middle. Well ... it depends!

Question

Is there anyway to get Software Delivery to resume a package download from an intermediate state, rather than restarting the package download over completely, when the package delivery mechanism is UNC? What about HTTP?

Answer

If you are using UNC, then the bad news is NO. This is called package checksumming and Checksums are only available via HTTP downloads, not UNC. There are two other things to note here.

1. Once a solid network connection is restored,if your package contains multiple files, the download will resume at the end of the last file successfully delivered, but only via HTTP. This is not supported on UNC...