Blocking processes to start on startup from a service & continue running service after some processes are down.

Question

I have a C++ windows service running on system privileges and I need to make some changes in some of my DLLs that are loaded to several windows processes (explorer.exe, etc.).

The only time to do so is when these processes are down. I'm trying to make to impact to the UX minimal, so I don't wan't to force quit those or to popup any annoying message boxes and ask the user to do so.

I have tried to start this task on the startup of my service, the issue is several of these processes start before I finished it.
I'm trying to understand if there is a way to delay the start of processes on Windows startup, until I finish my task. Is there any event or anything familiar that I can set that will block those?

The other option is to do the needed task on shutdown. I did not find a way to do so yet, and all the related questions seem a bit old (how to delay shutdown and run a process in window service ), and regard to older version of windows.

This solution needs to be compatible with Windows versions greater than 7.

Answer 1

You can do this by using MoveFileEx and setting MOVEFILE_DELAY_UNTIL_REBOOT which will replace the file at the next reboot.

This should be well before any other processes have started, but without more details on your usecase its hard to tell if this'll work for you. Either way, searching for this flag should give you lots of information about this kind of issue.

According to the documentation, this has been supported since XP.