Office 2013

Computer and processor : 1 gigahertz (GHz) or faster x86- or x64-bit processor with SSE2 instruction set

Memory (RAM) : 1 gigabyte (GB) RAM (32-bit); 2 gigabytes (GB) RAM (64-bit)

Hard Disk : 3.0 gigabytes (GB) available

Display : Graphics hardware acceleration requires a DirectX10 graphics card and a 1024 x 576 or higher resolution monitor

Operating System : Office 2013 runs on 32-bit and 64-bit versions of Microsoft Windows operating systems. When you run Office 2013 32-bit on a 64-bit version of a Windows operating system, the program runs in the 32-bit layer of the Windows operating system. For more information, see 64-bit editions of Office 2013. Here are supported Windows operating systems on which you can run Office 2013 32-bit and 64-bit programs.
Office 2013 32-bit products are supported on the following Windows operating systems:
Windows 7 (32-bit or 64-bit)
Windows 8 (32-bit or 64-bit)
Windows 8.1 (32-bit or 64-bit)
Windows Server 2008 R2 (64-bit)*
Windows Server 2012 (64-bit)**
Office 2013 64-bit products are only supported on the following Windows operating systems:
Windows 7 (64-bit)
Windows 8 (64-bit)
Windows 8.1 (64-bit)
Windows Server 2008 R2 (64-bit)*
Windows Server 2012 (64-bit)**
*Windows Server 2008 R2 is available only in 64-bit architecture
**Windows Server 2012 is available only in 64-bit architecture

Note:

No support is provided for side-by-side installations of 32-bit and 64-bit editions of Office. For example, there is no support for side-by-side installations of Office 2010 32-bit with Office 2013 64-bit, or for Excel 2010 64-bit and Visio 2013 32-bit.
Lync Server 2013 is available only in a 64-bit edition, which requires hardware and a 64-bit edition of the Windows Server operating system. A 32-bit edition of Lync Server 2013 is not available with this release.