Microsoft SQL Server 2008 Setup Error

I am trying to install SQL server 2008 but it shows the below error. I download .Net Framework 2.0 from the Internet and then installed it in my system; then I again tried to install this software but SQL shows the same error again. Can any one tell me its solution, so that I can install this software and can start my work?

Microsoft SQL Server 2008 Setup
SQL Server 2008 Setup requires Microsoft .NET Framework 2.0 SP2 to be installed.
Download and install .NET Framework from http://www.microsoft.com/net/ and then rerun setup.
OK
