I was installing additional new instance of SQL Server 2012 on a machine where other instance was installed earlier. In the process I run into the problem where Setup wuzard just frozen on about 99% on SqlEngineConfigAction_install_startup_Cpu64 step without flagging any errors and making no progress for hours, so that Setup window looks like that all the time:
I realized that I’ve seen it before but not made any efforts to fix it beyond starting process from scratch. This time I did some googling and found that there may be quite a few reasons for this problem, for example see this blog post: “Your SQL Server Setup may hang forever when it’s almost at the 99 %!” on MSDN Blogs. I tried a few suggestion with no luck but in the process I’ve noticed that Windows service for my new named instance has been already created but frozen in “Starting” state, so killing and restarting it manually revived SQL Setup Manager and it completed installation process with flying colors in a minute after this. So it seems SQL Setup Manager just endlessly waits for service started confirmation or something like this without any time out in place… Anyhow I’m just taking a note of my fix in case somebody else or myself run into this again.