Processor

Minimum: 400 megahertz (MHz) Pentium processor
Recommended: 1 gigahertz (GHz) Pentium processor

Operating System

.NET Framework 3.0 can be installed on any of the following systems:

  • Microsoft Windows 2003 Server Service Pack 1 (SP1)
  • Windows XP SP2
  • Windows Vista *

*Windows Vista comes with .NET Framework 3.0. There is no separate installation package required. The standalone .NET Framework 3.0 packages are not supported on Vista.

RAM

Minimum: 96 megabytes (MB)
Recommended: 256 MB

Hard Disk Up to 500 MB of available space may be required.
CD or DVD Drive Not required.
Display

Minimum: 800 x 600, 256 colors
Recommended:1024 x 768 high color, 32-bit

Mouse Not required

Installation drive

When you start the .NET Framework 3.0 installer, the default installation location is on your system drive, which is the drive that boots your system. Please ensure that the required amount of space (up to 500 MB) is available on your system drive.

Source MSDN