1 Read the warning, then choose More info
More info reveals the application name and publisher. Opening those details does not start Sill.
Windows portable beta · First launch
Understand the Windows warning.
Sill’s current beta is unsigned. Windows may ask you to make a trust decision before opening it. Here is what that screen means and how to check your download.
Why the blue window appears
Microsoft Defender SmartScreen checks the reputation of downloaded applications. A new or little-downloaded build can be unrecognized. Sill’s current beta also lacks a publisher code signature, so the details can say Unknown publisher.
This warning is not, by itself, a malware detection. It is also not proof that the file is safe. Download only from sillbrowser.com, check the release details, and proceed only if you trust that download. Signing is being arranged; the current beta remains unsigned.
Microsoft explains download reputation and code signing. A signature does not guarantee that every new build will avoid a reputation warning.
Start with the official ZIP
- Download the Windows x64 portable ZIP from the official download section.
- Right-click the ZIP and choose Extract All…. Extract the complete folder; do not run Sill from inside the ZIP.
- Open the extracted Sill folder, keeping its accompanying files together. Double-click Sill.exe. File Explorer may hide the .exe extension and show simply Sill, with type Application.
A portable ZIP does not use an installation wizard. Sill saves its profile separately in your Windows user account. Close an older Sill build before opening a newer one.
If you see “Windows protected your PC”
These are actual Windows 11 Sandbox captures of beta24. Your layout or wording may vary by Windows version and device policy.
2 Check Sill.exe before deciding to run
Check that App says Sill.exe. Unknown publisher is expected for this unsigned beta. If it is the official download you intended to open and you trust it, choose Run anyway to allow this launch. Otherwise choose Don’t run.
3 Sill opens to a fresh workspace
You should now see Sill's start page. This is beta24 running in the same isolated Windows Sandbox after the warning.
Keep Windows protections enabled. You do not need to disable SmartScreen or antivirus, add exclusions, or run Sill as administrator.
When to stop and get help
There is no Run anyway button
Smart App Control or an organization’s device policy may block unsigned apps and offer no override. This guide cannot change that. Keep those protections enabled; contact your device administrator or wait for a signed release. Microsoft’s Smart App Control guidance explains this distinction.
The message names malware or a potentially unwanted app
That is different from an unrecognized-app reputation warning. Do not use these steps to dismiss a threat detection. Stop and contact Sill support with the exact message, build version, and download source. Never send passwords or your browser profile.
The file came from another website or has a different name
Choose Don’t run. Return to the official Sill download page and check the current release. A familiar filename alone does not establish the source or integrity of a file.
How can I check the download hash?
The current release manifest lists the ZIP’s SHA-256 hash. Advanced users can compare it with Get-FileHash -Algorithm SHA256 in PowerShell. Match the hash for the exact version you downloaded; a matching hash checks consistency with the manifest, not a guarantee of safety.
Ready to explore?
Continue to setup & help Read current limitations
Windows 11 first-run screenshots. Windows 10 validation is still pending. No macOS, Linux, phone or tablet browser build is currently available.