I have been performing silent upgrades of ESRI GIS software since 9.2. My organization has custom VB.NET desktop applications that I have needed to uninstall before uninstalling the main desktop software. I was able to uninstall the custom VB.NET desktop applications using msiexec /x and the GUID for the custom desktop application that is found in the computer's registry.
I have been unable to find similar objects for Add-Ins. As such, has anyone had the need to silently uninstall Add-Ins when they upgraded their ESRI desktop GIS software? Can you provide some guidance/hints on how this would be accomplished.