diff --git a/.goreleaser.yaml b/.goreleaser.yaml
index eafa225..32e434a 100644
--- a/.goreleaser.yaml
+++ b/.goreleaser.yaml
@@ -14,7 +14,6 @@ builds:
     goos:
       - linux
       - darwin
-      - windows
     goarch:
       - amd64
       - arm64
@@ -33,10 +32,6 @@ archives:
 
     wrap_in_directory: "ace-{{ .Version }}"
 
-    format_overrides:
-      - goos: windows
-        formats: [zip]
-
 changelog:
   sort: asc
   filters:
diff --git a/docs/install.md b/docs/install.md
index ab7ced7..5dfb5ad 100644
--- a/docs/install.md
+++ b/docs/install.md
@@ -1,5 +1,14 @@
 # Installing ACE
 
+ACE supports Linux and macOS only. It does not build on Windows. On a
+Windows host, run ACE in WSL or in the container image. Keep its output
+directory on the Linux file system, not on a Windows drive: ACE protects
+reports with POSIX file modes, and Windows drives do not keep them.
+
+Reports written by earlier Windows builds keep their Windows ACLs, even
+after you move ACE to WSL. Other local users may be able to read the
+table rows in them. Delete these reports, or restrict their ACLs by hand.
+
 Choose the option that fits your environment:
 
 - Go install (fastest if you have Go toolchains)
@@ -30,7 +39,7 @@ Grab the prebuilt archive for your platform from GitHub Releases and unpack the
 
 ```sh
 ACE_VER=v1.9.0  # update to the latest tag from GitHub Releases
-OS=Linux    # or Darwin or Windows
+OS=Linux    # or Darwin
 ARCH=x86_64 # or arm64
 
 curl -fsSL "https://github.com/pgedge/ace/releases/download/${ACE_VER}/ace_${OS}_${ARCH}.tar.gz" -o /tmp/ace.tgz
@@ -39,8 +48,7 @@ sudo install -m 0755 /tmp/ace/ace /usr/local/bin/ace
 ```
 
 Notes:
-- macOS uses `Darwin`; Windows archives are `.zip`.
-- On Windows, place `ace.exe` somewhere on your `PATH` (e.g., `%USERPROFILE%\\bin`).
+- macOS uses `Darwin`.
 
 ## Run with Docker/Podman
 
diff --git a/pkg/common/secure_file.go b/pkg/common/secure_file.go
index 22fb78d..bd9fe43 100644
--- a/pkg/common/secure_file.go
+++ b/pkg/common/secure_file.go
@@ -21,6 +21,10 @@ import (
 // only *request* a mode, which the umask then masks off — under the usual 0022
 // that lands at 0644, readable by every local user. These helpers set the mode
 // explicitly so it does not depend on the operator's umask.
+//
+// Owner-only access here comes from POSIX mode bits. On Windows, os.Chmod
+// does not change the ACLs, so these helpers would not protect the files.
+// For this reason ACE does not build on Windows: see secure_file_windows.go.
 const (
 	SecureFileMode os.FileMode = 0o600
 	SecureDirMode  os.FileMode = 0o700
diff --git a/pkg/common/secure_file_windows.go b/pkg/common/secure_file_windows.go
new file mode 100644
index 0000000..856a698
--- /dev/null
+++ b/pkg/common/secure_file_windows.go
@@ -0,0 +1,21 @@
+// ///////////////////////////////////////////////////////////////////////////
+//
+// # ACE - Active Consistency Engine
+//
+// Copyright (C) 2023 - 2026, pgEdge (https://www.pgedge.com/)
+//
+// This software is released under the PostgreSQL License:
+// https://opensource.org/license/postgresql
+//
+// ///////////////////////////////////////////////////////////////////////////
+
+//go:build windows
+
+package common
+
+// ACE does not support Windows. The helpers in secure_file.go protect
+// output files with POSIX mode bits, and Windows does not use them for
+// access control: other local users could read reports that contain
+// table rows. This reference to an undefined name stops the build on
+// Windows, so nobody gets an unsafe binary by accident.
+var _ = ACE_does_not_support_Windows