With the release of Windows 8.1, Microsoft has also released .NET Framework 4.5.1 and Visual Studio 2013. If you have already installed Windows 8.1, .NET Framework 4.5.1 will come pre-installed with it. So you will not need to update the framework.
.NET Framework 4.5 comes installed with Windows 8. If you are using Windows 8, you will have version 4.5 installed. You can download the latest version from below and install it in Windows 8.
System requirements for .NET Framework 4.5.1 include the following:
A minimum free space of 850 MB for 32-bit Windows and 2 GB for 64-bit Windows is required for installation.
Supported Operating Systems include Windows 8, Windows 7 SP1, Windows Vista SP2 and Windows Server 2008 R2.
There are two types of installers available for .NET Framework 4.5.1 installation. The web installer will download the components during installation while the offline installer will download the complete installation which doesn’t need to connect to the Internet for further installation.
According to Microsoft:
The Microsoft .NET Framework 4.5.1 is a highly compatible, in-place update to the Microsoft .NET Framework 4 and the Microsoft .NET Framework 4.5. The offline package can be used in situations where the web installer cannot be used due to lack of internet connectivity.
Some known issues with .NET Framework 4.5.1 are given in KB2890857.
New features of .NET Framework are:
Performance and reliability improvements
The ability to suspend and resume operations in the ASP.NET page framework
The ability to compact large object heaps on-demand
64-bit Edit and Continue controls
The ability to trace and sample activities
Improvements that make SQL connections more resilient