In a surprise announcement, Microsoft said 800MHz processors from Intel, AMD and Via will be "Vista capable," while 1 GHz 32-bit or 64-bit processors are "Vista premium ready."
PCs will be required to have 1 GB of system memory to run Vista’s premium features, and 512 MB to run the OS’s core features.
Vista capable PCs should also have 20 GB of HDD and 15 GB of HDD free space, as well as a CD-ROM drive.
Microsoft defines Vista capable PCs as those that will "deliver the core Windows Vista experiences such as innovations in security, reliability organizing and finding information. They can also deliver key business features found in the Windows Vista Business and Windows Vista Enterprise versions, such as domain join."
"However, some premium features may require advanced or additional hardware," according to a Microsoft advisory.
Windows Vista premium PCs will be able to run the full range of Vista features, with improved productivity, enhanced visual quality and visual style, according to Microsoft.