Microsoft .NET Framework 4 Client Profile

Microsoft .NET Framework 4 Client Profile is a redistributable package which provides only a few features of the .NET Framework 4, and it has been developed specifically to enable fast deployment for WPF (Windows Presentation Foundation) and Windows Forms apps.

Setup process and support for 64 bit systems

It comes in the form of an EXE which you have to run, just like any other utility. However, if Microsoft .NET Framework 4 is already part of your operating system, the installation process will not run.
In addition to that, you should know that unlike older versions, this .NET Client Profile can be installed on both 86 and 64 bit architectures.

Better garbage collection and debugging

This package comes with improvements in a lot of areas, including CLR (Common Language Runtime), BCL (Base Class Library), Data Access and Modeling, WPF and Windows Workflow, and the list goes on.
To be more precise, now the concurrent garbage collection method is replaced with a background one, while debugging is much easier, including dump debugging, Watson minidumps and mixed mode debugging for 64 bit and code contracts.

Improvements in multi-core support, WCF and WPF

Better multicore support is provided, as well as better n-tier support with self-tracking entities, customizable code generation (with T4 templates), foreign key associations and test-driven development support.
When it comes to WCF Data Services (Windows Communication Foundation) has also received some improvements, such as data binding, row count, feed customization and a better request pipeline. Windows 7 multi-touch, ribbon controls, taskbar extensibility features and support for Surface 2.0 SDK are some of the enhancements Windows Presentation Foundation has received.

Bottom line

All things considered, Microsoft .NET Framework 4 Client Profile is a must-have on any computer, due to the many improvements it brings. It can be installed on any machine, regardless of the architecture and OS it is running on, and helps all users out there, not just the highly experienced ones.