Temporarily disable real-time protection. If installation succeeds, the AV is the cause.
Open Event Viewer → Windows Logs → Application . Look for error VCRUNTIME140.dll not found or 0xc000007b . filezilla not installing on windows 11
Always right-click the installer and select Run as administrator . If the issue persists, temporarily lower UAC to "Notify me only when apps try to make changes" (not recommended permanently). Cause 2: Windows SmartScreen / Defender Blocking Technical Explanation: FileZilla installer is code-signed but not always with an EV (Extended Validation) certificate. SmartScreen may flag it as "unrecognized," especially if downloaded via HTTP (not HTTPS) or from a mirror. Temporarily disable real-time protection
Compare file size and SHA-256 checksum of the downloaded .exe with the official values. Look for error VCRUNTIME140
Run the installer manually as Administrator: right-click → Run as administrator . If it works, UAC was the blocker.
| Symptom | Frequency | |---------|-----------| | Installer launches, then disappears without error | High (~40%) | | "Windows protected your PC" (SmartScreen) | High (~30%) | | "Installation directory is not writable" | Medium (~15%) | | Missing MSVCP140.dll or VCRUNTIME140.dll error | Medium (~10%) | | Installation hangs at "Registering services" or "Installing shell extension" | Low (~5%) | | Error 5 (Access Denied) when writing to Program Files | Low (~5%) | Cause 1: User Account Control (UAC) Blocking Elevation Technical Explanation: FileZilla installer requires write access to C:\Program Files\FileZilla FTP Client and registry keys under HKLM\SOFTWARE . Without administrative elevation, the installer cannot copy files or register protocol handlers (ftp://). Windows 11 may silently fail elevation if the executable is unsigned or untrusted.
Check Windows Security → Virus & threat protection → Ransomware protection → Controlled folder access → Block history . Look for FileZilla installer.