diff --git a/src/util/platform.cpp b/src/util/platform.cpp
index b177f65..7d4e70c 100644
--- a/src/util/platform.cpp
+++ b/src/util/platform.cpp
@@ -298,30 +298,50 @@ bool Platform::writeFileAtomically(const std::string& path,
 
 #ifdef _WIN32
     {
-        std::ofstream out(tmp, std::ios::binary | std::ios::trunc);
-        if (!out.is_open()) return false;
-        out.write(content.data(), static_cast<std::streamsize>(content.size()));
-        out.flush();
-        if (!out) { out.close(); DeleteFileA(tmp.c_str()); return false; }
-    }
-    // Flush the temp file's contents to stable storage before the rename.
-    HANDLE h = CreateFileA(tmp.c_str(), GENERIC_WRITE, 0, nullptr,
-                           OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
-    if (h != INVALID_HANDLE_VALUE) {
-        FlushFileBuffers(h);
+        // One handle for write + flush. CreateFileA with no SECURITY_ATTRIBUTES is NOT inheritable: the old
+        // std::ofstream (CRT) handle was, so a child spawned with bInheritHandles=TRUE at that moment (xmrig,
+        // runHiddenCapture) kept "<path>.tmp" open without FILE_SHARE_DELETE and every later MoveFileEx
+        // failed while it ran. Also no second share-mode-0 open, which silently skipped the flush whenever
+        // AV / the indexer had the new file open.
+        HANDLE h = CreateFileA(tmp.c_str(), GENERIC_WRITE, 0, nullptr,
+                               CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
+        if (h == INVALID_HANDLE_VALUE) return false;
+        bool ok = true;
+        size_t written = 0;
+        while (written < content.size()) {
+            const size_t left = content.size() - written;
+            const DWORD chunk = static_cast<DWORD>(left > (1u << 30) ? (1u << 30) : left);
+            DWORD n = 0;
+            if (!WriteFile(h, content.data() + written, chunk, &n, nullptr) || n == 0) { ok = false; break; }
+            written += n;
+        }
+        // Flush the temp file's contents to stable storage before the rename.
+        if (ok && !FlushFileBuffers(h)) ok = false;
         CloseHandle(h);
+        if (!ok) { DeleteFileA(tmp.c_str()); return false; }
     }
     (void)restrictPermissions; // owner-only ACLs rely on the per-user profile dir on Windows
-    // MoveFileEx with REPLACE_EXISTING is atomic on NTFS; WRITE_THROUGH makes it durable.
-    if (MoveFileExA(tmp.c_str(), path.c_str(),
-                    MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH) == 0) {
+    // MoveFileEx with REPLACE_EXISTING is atomic on NTFS; WRITE_THROUGH makes it durable. AV / the search
+    // indexer can hold the destination briefly (ACCESS_DENIED / SHARING_VIOLATION / LOCK_VIOLATION): retry
+    // a few times (20+40+80+160 ms worst case, only on a write that used to just fail) instead of dropping it.
+    BOOL moved = FALSE;
+    DWORD delayMs = 20;
+    for (int attempt = 0; attempt < 5; ++attempt) {
+        moved = MoveFileExA(tmp.c_str(), path.c_str(), MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH);
+        if (moved) break;
+        const DWORD err = GetLastError();
+        if (err != ERROR_ACCESS_DENIED && err != ERROR_SHARING_VIOLATION && err != ERROR_LOCK_VIOLATION) break;
+        if (attempt < 4) { Sleep(delayMs); delayMs *= 2; }
+    }
+    if (!moved) {
         DeleteFileA(tmp.c_str());
         return false;
     }
     return true;
 #else
     const mode_t mode = restrictPermissions ? 0600 : 0644;
-    int fd = ::open(tmp.c_str(), O_WRONLY | O_CREAT | O_TRUNC, mode);
+    // O_CLOEXEC: the background settings writer can race a dragonxd/xmrig fork+exec; don't leak this fd.
+    int fd = ::open(tmp.c_str(), O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, mode);
     if (fd < 0) return false;
     if (restrictPermissions) {
         ::fchmod(fd, 0600); // enforce even if the temp file pre-existed with looser perms
@@ -350,7 +370,7 @@ bool Platform::writeFileAtomically(const std::string& path,
     }
     // fsync the directory so the rename (the metadata that makes the new file
     // visible) survives a crash, not just the file contents.
-    int dfd = ::open(dir.empty() ? "." : dir.c_str(), O_RDONLY);
+    int dfd = ::open(dir.empty() ? "." : dir.c_str(), O_RDONLY | O_CLOEXEC);
     if (dfd >= 0) {
         ::fsync(dfd);
         ::close(dfd);