<p>For some reason, when I try to install <code>SQL Server 2008 Express</code>, I get an error saying that I need to have <code>.Net Framework 3.5</code> installed first, but the thing is: I already have! So could anybody tell me if I can bypass this verification by updating a registry key or something? I have np with visual studio or any other thing... just when I try to install sql express.</p>

I ran into this once before. Make sure that it is installed. Reinstall if necessary. I believe what I did was install SP1. SQL Server 2008 has a tendency of trying to install the Compact Framework 3.5 and based on the build or refresh of SQL, Compact Framework 3.5 SP1. HTH!