"Windows protected your PC"#

The first time you run the PrismDesk installer, Windows is likely to show a blue box:

Windows protected your PC Microsoft Defender SmartScreen prevented an unrecognised app from starting. Running this app might put your PC at risk.

Clicking More info reveals the app name, the publisher, and a Run anyway button.

This page is not here to tell you to press it. It is here to tell you what you can check first, because "just click through the warning" is exactly the habit that gets people hurt.

Why it appears#

SmartScreen is a reputation check, not a signature check. A file that few people have downloaded yet is unrecognised, and that is true even when it is correctly signed by a certificate from a public authority. Reputation accumulates as more people install the same signed file; a new publisher starts at zero and cannot buy its way past it.

So: the warning going away is a matter of time, and its presence says nothing about whether this particular file is what it claims to be. That question you can settle yourself, right now.

What you can check#

1. The publisher. In the SmartScreen box, click More info — the publisher line comes from the digital signature, not from the file name. You can see the same thing before running it: right-click the installer → Properties → Digital Signatures.

The publisher line has to read Masato Okumura. That is the name on the certificate PrismDesk is signed with — an individual-validation (IV) code signing certificate issued by SSL.com, not an EV certificate. If More info shows any other name, or says "Unknown publisher", the file you have is not the one we published: do not run it, and tell us.

An IV certificate means a certificate authority checked the identity of one named person, rather than a registered company. It does not carry the reputation head start that an EV certificate does, which is why SmartScreen still warns about the first few downloads.

2. The hash. Every release includes SHA256SUMS.txt. Compare it with what you downloaded:

Get-FileHash .\PrismDesk-Setup.exe -Algorithm SHA256

The line for that file in SHA256SUMS.txt has to match, character for character. Download both from the same place — https://github.com/Asynchronous-0x4C/prismdesk-app/releases — and if they ever disagree, do not run the file, and tell us.

3. A second opinion. Uploading the installer to VirusTotal is a reasonable thing to do with any executable from a small vendor, ours included.

The UAC prompt is a separate thing#

After SmartScreen, Windows asks for administrator rights. That one is not about reputation — the installer genuinely needs them, because it:

installs the virtual display driver into the Windows driver store, and adds the driver's signing certificate to the machine's Trusted Publishers,
adds six inbound firewall rules (one per port — see Set up over Wi-Fi),
creates the sign-in start-up entry, if you left that ticked — a Task Scheduler task, so that the host can start with administrator rights without asking you at every sign-in.

The virtual camera is not registered by the installer: the host registers it while it runs, unless you turn the camera off (see Webcam).

Uninstalling removes the driver, the firewall rules, the start-up entry and the camera registration. It does not remove the certificate from Trusted Publishers; to remove it, open certlm.msc → Trusted Publishers → Certificates and delete the Masato Okumura certificate.

What we do not do about it#

We do not ask you to disable SmartScreen, and we do not ship instructions for turning it off. It is doing its job; it just does not know us yet.