One of the hallmark features of Outlook 2003 is the attention given to the needs of "disconnected" and low-bandwidth users--those who don't have a full-time high-speed connection to the network at their office. Cached Exchange mode, "drizzle" connections to Exchange Server 2003, improvements to reduce the amount of data sent over the wire, and other changes provide a more efficient working environment for these Outlook users. What's less obvious is that Microsoft Office 2003 has a feature designed to help keep all the Office programs, not just Outlook, running well when a user is disconnected from the network: the local installation source (LIS).

The idea behind the LIS is to give users a local copy of the Office 2003 installation files so that if they need to repair or reinstall Office, add Office components, or update Office with a hotfix or service pack, they won't need a full connection to an administrative installation point on the network. If you want to deploy the LIS to users, you need to deploy Office by using the CD-ROM or a compressed CD-ROM image on the network--you can't use an uncompressed administrative installation point. Regardless of the installation source, you can still use the Custom Installation Wizard (CIW) from the Office 2003 Editions Resource Kit (ORK) to create an .mst transform file to govern the settings for your installation.

If you're planning to include the LIS in your deployment, be sure to download the most recent copy of setup.exe for Office 2003. This new version adds three new options for the \[Cache\] section of the setup.ini file: ENFORCECACHE, CACHEONLY, and REMOVECACHEONLY. ENFORCECACHE requires the target computer to have room for installing the full LIS; otherwise, Setup exits without completing the installation. The CACHEONLY option lets you deploy just the LIS; later, you can kick off the full Office installation (or installation of whatever components you chose in the CIW). Similarly, the REMOVECACHEONLY option removes only the LIS, leaving the actual Office installation intact. The ORK has details about these and other LIS options.

By default, Office 2003 stores the LIS in C:\msocache, a hidden folder that contains a folder for each Office product you installed. For example, if you have both Microsoft Office Visio 2003 and Microsoft Office Professional Enterprise Edition 2003 installed, each will have its own folder. If a drive other than C has more space or is formatted with NTFS instead of FAT, Office will first use the largest NTFS drive with sufficient space for LIS, then fall back to a FAT drive. Or, you can specify a drive with the LOCALCACHEDRIVE option in setup.ini.

If no available drive has room for the full cache, the Office setup program will try to create an LIS for just the installed features. This, by the way, explains why you will see a lot of different .cab files in the LIS folders. Instead of using one .cab file, Office 2003 uses many so that the source files needed by individual features can be cached separately.

The LIS takes up a lot of space, up to 290MB for Office Pro. Setup will not try to install the LIS unless the drive has plenty of free space-–2.5GB, if you're installing the full LIS and at least 1.5GB for an LIS that has just installed features. If you add a new, larger hard drive to a machine, you might want to move the LIS to it and thus free up space on the original drive. Just moving the Msocache folder won't work; Office won't know to look in the new location for the LIS. Also, if a user deletes the Msocache folder after installing Office with the LIS enabled, the next time you use the Office setup program to change or repair the installation, it will try to recreate the Msocache folder in the original location. To address these scenarios, Microsoft released a tool last month for changing the location of the LIS or removing it completely: Local Installation Source Tool (LISTool.exe).

When you run LISTool, you see three options: "Enable LIS," "Move the LIS to a different drive," and "Delete and disable LIS." You can use the "Enable LIS" option to create or repair the LIS after the Office installation.

You can move the LIS to another drive on your computer only if at least 290MB of space is free on a suitable drive; Microsoft recommends using a hard drive, not a USB or other drive that isn't permanently connected. LISTool moves the Msocache folder to the root of the selected drive and adjusts the necessary registry entries for the Office installation.

Under the "Delete and disable" option, you can choose which programs' LIS files to remove. Microsoft recommends that you not delete the Microsoft Error Reporting files or any LIS listed as "(web package)". Some Web packages might be designed to automatically download updates from Microsoft's Web site.

Deploying Outlook 2003 or Office 2003 with the LIS requires you to move away from the type of administrative installation points that you might have used for past deployments and to consider user disk capacity as a factor in how you deploy Office. Having the LIS available will make repairing an Office installation or installing patches easier for users, especially those who aren't permanently connected to the network.

New Setup.exe Fine Tunes Local Caching
http://www.microsoft.com/office/ork/2003/journ/newsetupexe.htm

Setup Settings File--\[Cache\]
http://www.microsoft.com/office/ork/2003/ref/RefA03.htm#sub_9

LISTool.exe
http://www.microsoft.com/office/ork/2003/journ/LISTool.htm