Bhavbhuti,
OK. I'm confused why you'd post a strong declarative statement (".NET Framework apps are slow"), based on misreading (15 seconds vs 30 seconds), uncertainty ("hard to say"), and the dangerous "assume".
By your own admission, you're lacking details. You've stated that you don't know what this app is doing at start-up. It's a known fact that the framework can take a few seconds (or longer) when launched the first time. What happens when the app is launched again? How long did it take?
What was your objective for initiating this thread? I won't make any assumptions as to why - but you may safely assume that I believe you had very little foundation to make the statement you made. Maybe if/when you can provide some more specifics, this would be a more valuable discussion.
Kevin