Microsoft is on a familiar mission: moving legacy Windows features into WinUI, the current native UI framework. But this time, the company is making a case that the modernization isn’t just cosmetic — it can actually be faster than the interfaces it replaces.
According to Microsoft’s Command Line dev blog, the new Windows 11 Run dialog (the Win+R tool) has been rebuilt on a modern C#/WinUI 3 stack, and by Microsoft’s own benchmarks it loads faster than the old Win32 version.
That’s a notable claim, given the long-running perception that swapping Win32 for WinUI/XAML makes Windows slower. Let’s break down what changed, how Microsoft pulled it off, and what it means for the rest of the OS.
The numbers behind the speed improvement
Microsoft’s benchmark figures are specific. The new Run dialog, built using C#/WinUI 3, has a 94ms median time-to-show. The legacy Run dialog, built on Win32, clocks in at 103ms median.
That’s a 9ms gap — a roughly 8.7% improvement, mathematically. Microsoft didn’t just slap a new skin on the old dialog; it rewrote the underlying implementation and measured the result against the prior version.
You’re unlikely to notice a 9ms difference with your eyes, but the methodology matters. Microsoft shared internal benchmark numbers in its post, treating the speed gain as a deliberate engineering outcome rather than a happy accident.
How Microsoft made it faster
The key technical detail is .NET AOT, or Ahead-of-Time compilation. The new Run dialog is a native WinUI 3 app written in C#, but instead of waiting for the normal .NET JIT (Just-in-Time) compiler to translate its code at launch, it’s compiled ahead of time.
Microsoft describes this as giving the dialog “the blazing speed of native code” while keeping the C# and WinUI 3 framework. In practice, that means the app doesn’t pay the startup overhead you’d normally expect from a managed .NET app.
Microsoft also says it worked with teams across the Windows platform to get these surfaces loading quickly — so the win isn’t simply WinUI being faster than Win32 by default. The platform-level improvements, per Microsoft, don’t just make Run fast; they help make the whole OS more efficient.
What about Task Manager and File Explorer?
Here’s where the skepticism comes in. There’s plenty of evidence that modernizing other surfaces has made Windows 11 slower, not faster.
The new Task Manager is noticeably slower than the old one on low-end PCs. File Explorer was criticized for being painfully slow until Microsoft began rolling out performance upgrades — and even after those fixes, it still isn’t as fast as the Windows 10 version. On a Windows 11 machine, you can literally watch the context menu populate items when you right-click a folder.
So the Run dialog’s speed is somewhat of an outlier. Microsoft has itself acknowledged that WinUI needs serious performance work, and it promised performance boosts ahead of the Task Manager rewrite. The Properties Sheet and AutoPlay dialog are also being modernized, but Run is the one where Microsoft landed a genuine speed win.
Why the Windows 11 Run dialog is the perfect test case
Microsoft chose a tough ask here. The old Run dialog has been around for more than 30 years, and it already appeared instantly. If WinUI has noticeable startup overhead, Run is arguably the worst feature to modernize — there’s nowhere to fall except below a dialog that was already fast.
“We knew the existing dialog was fast,” Microsoft said. The goal was to “maintain the same performance” while adding the dark theme, modern icons, and WinUI elements that define the current Windows 11 look.
The real story is that Microsoft rewrote a lightweight, time-tested surface and didn’t introduce the performance regression you’d normally expect. And Microsoft believes there’s still room for improvement — it hasn’t hit the ceiling yet.
What This Means for You
For most users, the practical takeaway is simple. The new Run dialog is optional — you have to turn it on. If you want it, go to Settings > System > Advanced and enable the modern version. Otherwise, the legacy Win32 dialog stays as-is.
The dark theme and modern icons are a bonus for those who want them, but the speed improvement is the headline. And if Microsoft’s platform-level optimizations do spread to other parts of Windows 11, you could see File Explorer and Task Manager catch up to — or even beat — the Windows 10 experience.
How to Get It
To try the new Windows 11 Run dialog, open Settings, navigate to System > Advanced, and toggle on the modern version. The legacy dialog remains available if you leave the setting off, so there’s no risk of a forced upgrade.
Under the surface, there’s a quiet bet being made about Windows 11’s future. The alternative to WinUI is WebView — a browser-based UI that most power users have long resisted. If Microsoft can keep modernizing without sacrificing speed, WinUI becomes the more defensible choice for the long term.
Source: Windows Latest
Over to you: Will you turn on the new WinUI Run dialog, or stick with the fast legacy Win32 version for now?
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