[This version of Windows Defender is still in development, so some Help information might be inaccurate or missing.]

System requirements for installing Windows Defender

To install Windows Defender, you must be logged on as Administrator or be a member of the Administrators group. Your computer or all computers on a network for which you want to install the program must meet these requirements.

Processor Pentium 233 MHz or higher processor; Pentium III recommended
Operating system Microsoft Windows 2000 Service Pack 4, Windows XP Service Pack 2, or Windows Server 2003 Service Pack 1
Random Access Memory (RAM) 64 MB RAM (minimum); 128 MB RAM (recommended)
disk space 20 MB of available hard disk space
Web browser Internet Explorer 6.0 or later

Notes