http://www.microsoft.com/windows/ie/ie7/about/sysreqs/default.mspxsystem requirements
Below are the minimum requirements your computer needs to run Internet Explorer 7. Some components may require additional system resources not outlined below.
Internet Explorer 7 will run on Windows XP Service Pack 2 (SP2), Windows XP Professional x64 Edition, and Windows Server 2003 Service Pack 1 (SP1). Memory requirements listed below are for Internet Explorer itself. Any machine with the recommended amount of memory for Windows (for example, 128 MB for Windows XP and 256 MB for Windows XP Professional x64) will meet the memory requirements for Internet Explorer 7.
Minimum Requirements
Computer/Processor Computer with a 233MHz processor or higher (Pentium processor recommended)
Operating System Windows XP Service Pack 2 (SP2)
Windows XP Professional x64 Edition
Windows Server 2003 Service Pack 1 (SP1)
Memory For Internet Explorer 7:
Windows XP Service Pack 2 (SP2) - 64 MB
Windows XP Professional x64 Edition - 128 MB
Windows Server 2003 Service Pack 1 (SP1) - 64 MB
Windows Server 2003 Service Pack 1 ia64 - 128 MB
Drive CD-ROM drive (if installation is done from a CD-ROM)
Display Super VGA (800 x 600) or higher-resolution monitor with 256 colors
Peripherals Modem or Internet connection; Microsoft Mouse, Microsoft IntelliMouse, or compatible pointing device