Minimum: 400 megahertz (MHz) Pentium processorRecommended: 1 gigahertz (GHz) Pentium processor
.NET Framework 3.0 can be installed on any of the following systems:
*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.
Minimum: 96 megabytes (MB)Recommended: 256 MB
Minimum: 800 x 600, 256 colorsRecommended:1024 x 768 high color, 32-bit
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