Microsoft is modernizing Windows by transitioning legacy features to its WinUI framework, including a redesign of the Run dialog. The new Run dialog, implemented with C#/WinUI 3, shows improved performance with a median time-to-show of 94 milliseconds, compared to 103 milliseconds for the legacy version, reflecting an 8.7% speed increase. Despite this improvement, Microsoft acknowledges that WinUI requires further performance enhancements in various areas. The development of the Run dialog utilized .NET AOT compilation to achieve native code speed while maintaining C# flexibility. Concerns about performance on lower-end machines persist, as seen with the Task Manager and File Explorer. Microsoft aims to modernize Windows features without sacrificing performance, with the Run dialog serving as a potential model for future updates.