MSI: Start service unless user choses to reboot machine

I am working on MSI installer which installs and starts the service. It may or may not replace files in use. When it does, there is a prompt to reboot machine at the end of install.

Service runs lengthy initialization on the first startup, which is undesirable to interrupt by shutdown. What I am trying to do is to prevent service from starting until it is known that setup completed, and there will not be a reboot, e.g.: reboot not needed or user selected to postpone reboot.

Bootstrapper is not an option, all must be implemented inside an MSI

Can somebody advise me, what's the best way to do this?

I'm going to give a pragmatic although not perfect answer.... Windows Installer doesn't really have any way to support this so just intentionally request a reboot and don't have a ServiceControl element. Just set the ServiceInstall to Auto and let the reboot take care of the rest.

I know, I usually try to avoid reboots also but if you are frequently likely to need one anyways well it just makes your whole story simpler.

The only other thing I can really think of is to expose an RPC mechansim in your service ( wcf end point for example ) and have your long running process only take place on either the second start of the service or when that rpc is invoked the first time. Then have a custom action at the end of the installer call the rpc if a reboot is not required.

I just can't think of any way to do it natively in MSI.