To apply the MSP patch file to an Adobe 9.1 MSI installer, try this:

  1. Download Adobe 9.1 MSI from here: ftp://ftp.adobe.com/pub/adobe/reader/win/9.x/9.1/enu/
  2. Download the latest 9.1 MSP patch file from here (currently 9.1.3): ftp://ftp.adobe.com/pub/adobe/reader/win/9.x/9.1.3/misc/
  3. Put these files in the same directory.
  4. Open up a command prompt, then navigate to that directory.
  5. Run the following command:
    msiexec /p AdbeRdrUpd913_all_incr.msp /a AdbeRdr910_en_US.msi /qb

This will apply the 9.1.3 patch directly to the 9.1 MSI file, ready for deployment. You can now deploy Adobe Reader 9.1 safe in the knowledge that it’s already patched to 9.1.3 😀