You have just downloaded the Correctify Windows app, you double-click it, and a blue screen blocks your way: “Windows protected your PC”. The first instinct is understandable: delete the file. Yet this message does not mean what most people think. Let’s take two minutes to explain it honestly, without jargon, and to give you the means to check for yourself rather than take my word for it.

This message does not mean “virus detected”

The blue screen comes from Windows SmartScreen, a filter built into Windows 10 and 11. Many people mistake it for an antivirus that found something. That is not its job: SmartScreen does not analyse the contents of the program, it assesses its reputation. In other words, it is not asking “is this file dangerous?” but “do I already know this file?”.

To answer, it mainly looks at two things: does the program carry a paid code-signing certificate identifying its publisher, and has it already been downloaded and run by a lot of people? If the answer is no on both counts, the app is simply unknown, and Windows would rather warn you. A perfectly clean piece of software released last week triggers exactly the same warning as a shady one: SmartScreen cannot tell them apart, because it does not judge the code.

That is also why the message comes back with every new version: each update produces a different file, so a “brand new” file that has to build its reputation all over again.

Why Correctify isn’t signed (yet): a matter of budget

Making this warning disappear means buying a code-signing certificate from a certificate authority. That certificate costs several hundred euros a year, has to be renewed annually, and involves an identity-verification process for the publisher.

But Correctify is a free project, with no ads and no subscription, that I build in my spare time, in the evenings and at weekends. The app earns me nothing: there is no account to create, no paid tier, and you use your own API key with the AI provider of your choice, which means even the cost of the corrections does not go through me. Spending several hundred euros a year on a project that generates no revenue, purely to avoid a blue screen, is not reasonable right now. I would rather be upfront about it than pretend otherwise.

The good news is that reputation also builds itself. As the app gets downloaded and run, SmartScreen eventually treats it as known and goes quiet, without any certificate being bought. And if signing becomes affordable one day, it will be put in place: the goal really is to make that screen go away.

Don’t take my word for it: check

“It’s safe, I promise” is exactly what a piece of malware would say too. So the right answer is not trust, it is verification. Here is what you can do, for free, in two minutes.

1. The public VirusTotal report. The installer is scanned by more than 70 antivirus engines through VirusTotal, and the report can be read by anyone from the Security section of the Windows page. You need to install nothing to read it.

2. The SHA-256 hash, to be sure it is the very same file. A scan report is only worth something if it covers the file you actually downloaded. The SHA-256 hash is a kind of unique serial number: two identical files share the same hash, and the slightest change turns it into something completely different. The installer’s hash is published on the Windows page; to compute your own file’s hash, open PowerShell and type:

Get-FileHash "$env:USERPROFILE\Downloads\Correctify Setup *.exe" -Algorithm SHA256

If both hashes match, your file is the one that was scanned, byte for byte. If they differ, do not open it and download it again from the official site.

3. Look at what the app does with your data. The text you correct goes straight to the AI provider matching your key (Google Gemini, OpenAI or Anthropic), and the correction comes back to you. There is no intermediate server, no account, and nothing is kept on my side.

Installing anyway, in three clicks

Once you have checked, getting past the blue screen takes three steps:

1. On the “Windows protected your PC” window, click “More info”, the discreet link under the text.
2. The file name appears, along with a new button: “Run anyway”.
3. Click it, and the installation proceeds normally.

You are only asked once: after installation, updates are installed on their own in the background, without going through that screen again.

What if the download itself is blocked?

Some browsers, Chrome first among them, go further and simply refuse to save an uncommon .exe, with a “dangerous file” message or a download that vanishes from the list. That is why the Windows page also offers the same installer packaged as a .zip: the browser lets the archive through, you open it, and you run the installer inside. The file is strictly identical, only the wrapping changes.

Either way, only download the app from the official page. An installer grabbed from a third-party download site may well have been altered, and that is precisely where the SHA-256 hash earns its keep.

In short

“Windows protected your PC” means “I don’t know this program yet”, not “this program is dangerous”. Correctify isn’t signed because a certificate costs several hundred euros a year and the project is free and built in my spare time. In exchange for that small inconvenience, you get the means to check: a public VirusTotal report, a SHA-256 hash to compare, and no data passing through my servers.

Ready to give it a go? Head to the download page, and if you don’t have an API key yet, our step-by-step guide gets you one in a few minutes.