Dude, Where's My Disk?

Windows Installer 3.0 reduces prompts for CD-ROMs and other installation sources, but it cannot eliminate them. Shown here is a typical request for an application installation source, such as the application CD-ROM or a path to a file share where the application’s installation package has been copied. This prompt appeared while applying a patch to a newly installed retail copy of Office 2003 Professional Edition. Installation source prompts are bothersome for individual users, but very problematic for organizations trying to patch large numbers of computers at once.

Prompts like this appear when the Installer needs to access an application’s installation source but is unable to locate one. This can happen for several reasons, including the following:

A patch applies only to a specific file version that is not present on the target computer. For example, installing “differential” patches, which deliver only the changes to an application’s files rather than complete files, requires access to specific versions of the files being changed. In the past, this forced the Installer to go back to an installation source and prompt if the source was unavailable. Windows Installer 3.0 makes such prompts less likely by selectively copying and retaining files for application “baseline” versions, such as the application’s last installed service pack. Patches that target these baseline versions will usually not require an installation source.