Windows 7 SP1, Windows Vista SP2, Windows Server 2008 SP2, and Windows Server 2008 R2 SP1.
Approximately 850 MB for 32-bit (x86) and 2 GB for 64-bit (x64) systems. How to Install .NET Framework 4.5 Offline How to download and install .Net framework 4.5 microsoft net framework 4.5 offline installer
Note: Windows 8 and Server 2012 already include .NET 4.5 by default. 1 GHz or faster. RAM: 512 MB minimum. Windows 7 SP1, Windows Vista SP2, Windows Server