Installing Patches

The recommended method for installing Personal Communications fix packs in conjunction with administrative installation images is as follows:
  1. Install Personal Communications from an administrative installation image that has no fix packs applied.
  2. Distribute the fix pack patch (.msp) files to the client machines.
  3. Install the patch files locally on the client machines.

This procedure significantly reduces the data that need to be transferred to each client machine. This also avoids the restriction detailed in Applying Fix Packs to a Local Client. If the recommended procedure cannot be used, see Applying Fix Packs to an Image for the necessary conditions.

For more information on using Windows Installer command-line parameters to install patches, refer to the Microsoft® Windows Installer SDK at http://www.msdn.microsoft.com.

When we build an ISB patch file, it contains the "delta" information to change the base level of the program (GM/CSD) to that ISB level. It does not contain the delta information to change any previous ISB's to that ISB. The patch can be applied directly to the PCOMM program OR it can be applied to an administrator image, which can then be used to install PCOMM on a client machine. We'll look at these two cases separately.

CASE 1 - Installing patches directly to a PCOMM program: When the first patch file is applied to a program, MSI makes all of the changes from the patch file AND it caches the delta information from the patch. For example, let's say we're applying ISB2 as the first patch on PCOMM 5.6 CSD1. When the second patch is applied, let's say it's ISB3, the patch does not contain the information to convert the program from ISB2 to ISB3. So MSI uses the cached delta information from ISB2 to essentially convert the program back to the CSD1 level so that it can then apply the ISB3 patch.

CASE 2 - Installing patches to administrator images: When the first patch is applied to an administrator image, MSI does NOT cache the delta information from the patch. MSI simply applies the delta to the administrator image, which creates a new image at the CSD1 ISB2 level (using the example from above). Once the ISB2 patch is applied to the administrator image, there is no way to figure out the original contents of CSD1. If a user then tries to apply ISB3 to this administrator image, MSI complains that it doesn't know how to apply the ISB3 deltas to the ISB2 level of the program. Unfortunately MSI uses it's own terminology to tell the user about this problem, saying something about incorrect product codes (or product id's, or something equally as meaningless to our users, I'm just not sure exactly what it says). The same (or similar) error message appears when you try to apply ISB3 directly to a PCOMM machine that has been installed from an administrator image at the CSD1 ISB2 level.