If you want to install Microsoft Office 2013 on your Windows XP or Windows Vista computer, you are out of luck. You need at least Windows 7 in order to be able to run the newest version of Office.
It’s no surprise Microsoft is now dropping support for Windows XP, but it is surprising Vista is dropped as well.
As per the FAQ of the Office 2013 Preview:
Installing the Preview
What are the system requirements?
Preliminary system requirements for the Preview include the following,
Computer and processor: 1 GHz or greater x86/x64 Processor with SSE2 instruction set
- Memory: 1 GB RAM (32-bit) / 2 GB RAM (64-bit)
- Hard disk: 3.5 GB free disk space
- Operating System: Windows 7, Windows 8, Windows Server 2008 R2 or newer
- Graphics: Graphics hardware acceleration requires DirectX10 graphics card and 1024×576 resolution