Four verified fixes for the most common reasons Obsidian fails to install on Windows 10 and Windows 11. Follow in order — most users are fixed by Fix 1 or Fix 2.
Windows SmartScreen Block 95% of cases
SmartScreen shows a warning for any newly released executable that hasn't yet accumulated enough reputation in Microsoft's database. This is the #1 cause.
Antivirus Interference Common
Real-time antivirus protection (Windows Defender, AVG, Avast, Malwarebytes) can quarantine or block the installer mid-write.
Permission or Path Error Occasional
Installing to a protected system folder (e.g. C:\Program Files) without admin rights causes a silent failure.
Corrupted Download Occasional
A partial or interrupted download produces a damaged .exe that fails to extract.
When you see "Windows protected your PC":
github.com/obsidianmd/obsidian-releases — the official Obsidian repository. SmartScreen flags it because Obsidian releases updates frequently and each new .exe starts with zero reputation.
For Windows Defender: Settings → Windows Security → Virus & threat protection → Manage settings → Real-time protection → Off.
Obsidian-1.12.7.exe from your Downloads folder.Obsidian-1.12.7.exe → Run as administrator.C:\Users\YourName\AppData\Local\Obsidian instead.