Microsoft .NET Framework 4 standard in Windows 8

thats what their site says) The .NET Framework 4 works side by side with older Framework versions. Applications that are based on earlier versions of the Framework will continue to run on the version targeted by default. The Microsoft .NET Framework 4 provides the following new features and improvements:

• Improvements in Common Language Runtime (CLR) and Base Class Library (BCL)
• Performance improvement including better multicore support, background garbage collection, and profiler attach on server.
• New memory mapped file and numeric types.
• Easier debugging including dump debugging, Watson minidumps, mixed mode debugging for 64 bit and code contracts.
• For a comprehensive list of enhancements to CLR and BCL go here.
• Innovations in the Visual Basic and C# languages, for example statement lambdas, implicit line continuations, dynamic dispatch, and named/optional parameters.
• Improvements in Data Access and Modeling

The problem is that some current software may need older versions of .NET Framework to function, thus Windows 8 users have to install older versions of .NET Framework. It is troublesome and the Windows is not clean, compared to Windows that has older versions of .NET Framework bundled within itself.