If you are trying to create MSP files ( aka MSI patches ), one of the best tool I found to create PCP files is
Wix. The amount of documentation for MSP creation is extremely small in my opinion, most of the required hints are in the Wix documentation. However I want to emphasize some of the steps that might be skipped by mistake:
- You need MSIMSP Wix automates the creation of PCP files only. It's not a one stop shop
- MSIMSP doesn't work with compressed MSIs. Yes! It's true, do not try to bend this rule.
Otherwise the process it's fairly simple. Type the wxs file (using your favorite text editor), compile the file to PCP and run MSIMSP tool after having administrative install MSIs (uncompressed versions).
A good start to more information about Windows Installer can be found
here