Custom action sequencing a rather special case (BasicMSI IS2022)
I have a rather large and complex BasicMSI installer for a large suite of application. One particular application in this suite is a windows service which (some of the time) will be running a child process. During installation if the service is shutdown manually first then all is fine but if the child process is running the installer detects that there is an application it cannot update without a reboot AND it checks this before stopping any services that might need to be updated. Now it might be the case (in an upgrade install) that this child process needs to be updated with a newer version. If I add a custom action (InstallScript action) to set a particular named registry value then the service and or the child process could monitor this and 'know' that installation was in progress and ensure this child process makes a hasty exit so it can be updated if necessary. I had in mind a value which would hold the hMsi aka HWND of the installer (to be set by a custom action at the start and cleared at then end) as its something that should be non-zero and which can be validated (albeit awkwardly). The PROBLEM however is that the custom action cannot be sequenced early enough in the execute sequence. The (restart manager) checks on running programs occur first it would seem. I'm wondering if there might be a better solution or whether its possible to do this from a custom action in the UI sequence instead of in the execute sequence. I need to write to a key under HKEY_LOCAL_MACHINE. Any suggestions?
