SQL Server 2008 Setup requires Microsoft .Net framework 3.5 to be installed

I was installing SQL 2008 the other day and kept getting the following error:

"SQL Server 2008 Setup requires Microsoft .Net framework 3.5 to be installed"

I tried running the .NET Cleanup and reinstalling with no luck. It turns out that this error was being cause by a bad download of the SQL 2008 Standard Media from the MS Site. I downloaded the product again without issue.