Rust in Windows is real, but Microsoft is not rewriting the whole operating system. A few kernel and graphics pieces already run on Rust, a bigger port is under way, and the “no more C and C++ by 2030” line was a research goal, not a Windows roadmap.
Headlines keep mixing those three things together. Here is how to tell them apart.
Quick facts first, so you can skim:
- Microsoft says about 70% of its product security bugs come from memory errors in C and C++.
- Parts of the Windows graphics stack already ship in Rust.
- Microsoft engineer Galen Hunt called his C/C++ elimination goal a “research project.”
- Nothing here changes what you do on your PC today.
Those numbers explain why any of this is happening at all.
Why Microsoft wants Rust in Windows at all
C and C++ let programmers manage memory by hand. That is fast, but one slip can let an attacker run code. Microsoft has said roughly 70% of its vulnerabilities trace back to this kind of error.
Rust blocks most of those mistakes before the program even compiles. That is the whole pitch: fewer exploitable bugs without slowing things down.
You see the cost of the old approach every month. Our look at October 2026 Patch Tuesday shows how many fixes land when a codebase is decades old.
What has actually shipped in Windows so far
Microsoft announced in 2023 that it would rewrite parts of the Windows kernel in Rust. Since then, Azure CTO Mark Russinovich has said the company is “all-in on Rust.”
The clearest shipped example is GDI region code. According to The Stack, Russinovich said it is “shipping now officially in your Windows systems.” The same report says work on Win32k, a long-running source of kernel bugs, is in progress.
This table separates what is confirmed from what is still a plan:
| Piece of Windows | Status | What it rests on |
|---|---|---|
| GDI region code (graphics) | Shipping | Mark Russinovich said it is “shipping now officially,” per The Stack |
| Win32k (windowing and graphics) | In progress | Microsoft is working on a port, according to the same report |
| DirectWriteCore font code | Ported, ship date unclear | Two developers ported about 154,000 lines of TrueType code in six months |
| AI code-translation project | Research only | Galen Hunt called it a research project, not a Windows plan |
| Rust kernel drivers (WDK) | Experimental | One 2026 explainer says it is not ready for production drivers |
The takeaway: the shipped list is short and specific. Be wary of any article that says “the Windows kernel is now Rust.”
The “eliminate C and C++ by 2030” post, explained
In December 2025, Microsoft Distinguished Engineer Galen Hunt posted on LinkedIn about a goal to remove every line of C and C++ from Microsoft by 2030. His slogan was “1 engineer, 1 month, 1 million lines of code.”
The reaction was loud, so Hunt updated the post. He said his team’s project is “a research project” building tools to move code between languages, as InfoWorld reported. He also said it was not meant to set a new strategy for Windows 11 and beyond.
That nuance matters. A research team using AI to translate code is very different from Windows 11 being rebuilt next year.
The October 27 claim you may have seen
A tech news roundup dated October 27, 2026 says Microsoft rewrote critical kernel sections from C++ to Rust. We could not find a Microsoft announcement that backs that wording.
It may be a loose summary of the earlier GDI and Win32k work. Treat it as unconfirmed until Microsoft publishes details.
There is also a real technical caution. Software engineer Wolfgang Grieskamp warned that naive automatic conversion from C or C++ to Rust tends to produce slow or unsafe code. Good Rust needs a rethink of the design, not just a line-by-line swap.
If you like this angle, see how Claude handled a huge Rust port in tsc-rs, the TypeScript compiler in Rust.
What Rust in Windows means for you
For most people, nothing changes this week. You will not see a new setting, and no update note will say “now with Rust.”
The benefit, if it works, is quiet: fewer memory bugs in graphics and font handling, which attackers like to target. Driver makers may eventually write Rust drivers too, though one 2026 explainer says Rust driver support is still experimental.
Keep installing Windows updates as they arrive. That is still your best protection while the old code remains.
Frequently Asked Questions
Is Windows being rewritten in Rust?
Not entirely. Some parts, such as GDI region code, already run on Rust, and more work is in progress. A full rewrite has not been announced.
Will Rust make Windows 11 faster?
Microsoft’s stated goal is security, not speed. We found no official performance claims.
Does Windows 11 still use C and C++?
Yes, the vast majority of it. The Rust work covers a small, growing set of components.
Do I need to change anything on my PC?
No. Keep Windows Update on and install patches as normal.
My take: judge Microsoft by what ships
Rust is a smart bet for Windows security, and the shipped GDI work proves it is more than a slogan. But the 2030 headline is a research goal, and the October 27 kernel claim is still unconfirmed. Wait for Microsoft to name specific components and Windows builds before you believe any “rewrite” story.
Leave a Reply