Here are the minimum system requirements for Messenger 8.0 (from the MSN website):

• Pentium 233 MHz processesor (500 MHz or faster recommended)
• Microsoft Windows XP or new Operating System
• Minimum 128 MB of RAM (at least 256 MB recommended)
• Up to 50 MB of hard disk space for installation, 15 MB to run the program.
• Microsoft Internet Explorer version 6 SP1 or later must be installed on your computer, though it does not need to be your default browser.
• Minimum 800 x 600 screen display resolution

No big changes since the MSN 7.5 release. Similar to MSN 7.5, version 8.0 will also require Windows XP or newer (users of Windows 2000, ME and 98 will need to keep using MSN 7.0).