This sounds really, really strange. As far as the file in Config.msi, I'm at a loss to explain why this is happening. I would post the logs of the first scenario: 1. Base Install log 2. Patch 1 install log 3. Patch 2 install log Error 1706 has two components: The first being, something is happening which requires source. Mostly likely in this case the removal of a binary patch of file(s), since it needs to rewrite the original version of the file. The second component is the original *.msi is not accessible in the place where you installed it from. If it's a network location, that location is inaccessible. If it's the local machine, the file probably has moved. Again, a log file will help diagnose this. ... View more