What it needs
Windows 10 version 1607 (build 14393) or newer, or Windows 11, on a 64-bit Intel or AMD processor. Not Windows on ARM: there the app says so and closes. Right-click the file → "Run as administrator"; there is nothing to install.
Check what you downloaded
Every published build has a SHA-256, shown under the download button. Compare it before you run the file:
Get-FileHash .\w0a-*.exe -Algorithm SHA256
Not identical, character for character? Delete the file. The app checks its own updates the same way.
Download only from here
We link the file only from this site; it is hosted on our own GitHub releases page. w0a.org and w0a.io are ours too and redirect here. A mirror, a download portal or a wrapped installer is not us.
If Windows warns you
A new release can show a blue "Windows protected your PC" box. That is SmartScreen: Windows has not yet seen the file run on many PCs — not because anything was found in it. If the digest matched: More info → Run anyway.
Some antivirus products flag any tool that edits the registry, on heuristics rather than a signature.
If your antivirus removed the file
What works without paying
The free tier is not a demo: live sensors, the Benchmark, the 39-switch Optimizations page, CS2 launch options and video config, DNS and ping tests, the Fix cards and the full backup and revert system all work without a licence. A plan opens the ten pages that go deeper.
Age
You must be at least 16 years old to use w0a. If you are under 18, only with your parent's or guardian's consent.
If something goes wrong
The support centre has a page for each of the usual first-run problems, and every one of them is written before you need it rather than after.