My service automatically starts during install...
Error 1920: this error would seem to indicate a missing privilege (logon as a service) or access right, or perhaps some sort of interference from an external cause or perhaps an MSI package that is not running elevated (unlikely I think - then you can only write to per-user paths).
regular user account? (about the above service accounts). LogonAsService="yes" for the User(element) in question. I believe this adds the privilege for the account (SeServiceLogonRight).InstallPrivileges).JSON format, it can obviously be in several formats: XML, registry, INI, etc... See OP comment above for more details.Timeout: As to the long timeout. I have seen this sometimes with security software (locks the whole setup so the service timeout runs only after some scanning delay), or with setups that trigger the creation of a system restore point prior to the installation kicking off in the first place (this is one of the possible reasons why some MSI installations suddenly take a long time when they ordinarily complete quickly - it is possible to prevent this restore point creation - MSIFASTINSTALL). Also, maybe check this answer from serverfault and the registry value described for whether there is a policy on your network to change the default service start timeout: How do I increase windows service startup timeout (ServicesPipeTimeout). Frankly I am not sure whether MSI uses its own timeout or the system default one - maybe someone can illuminate? One could also speculate that the database connection you initiate has its own timeout? (doesn't match your interactive test experience?) Maybe you can check your code and your call and let us know? Does your service depend on another service? (see symantec link below). Any dependencies to files installed to the GAC or to WinSxS as mentioned by Chris in the first link below?
A lot of speculation. Let's hope some of it helps or that it inspires other ideas that solve the problem. Below some links for safekeeping (trying to write a generic answer that may also help others with the same or similar problems - which makes the answer too long, sorry about that).
Links: