Final answer:
The best SDLC model for designing the new version of Windows is the Spiral model, due to its emphasis on iterative development, extensive testing, and risk analysis, which accommodate the complex nature of the project.
Step-by-step explanation:
The best SDLC (Software Development Life Cycle) model for designing a new version of Windows would likely be the Spiral model. This model combines iterative development (prototyping) with the sequential, linear development aspects of the Waterfall model. It provides a systematic approach to building software where testing plays a significant role in each iteration, ensuring any weaknesses in the design are identified and addressed early on.
Given that a complex product like Windows must go through comprehensive and continuous development cycles, the Spiral design process is ideal because it emphasizes risk analysis, extensive testing, and refinement over multiple iterations before the final product is released. It can handle the vast scope and changing requirements often encountered in such large-scale projects.