diff --git a/src/worker/config.cpp b/src/worker/config.cpp
index 5018da7..d327777 100644
--- a/src/worker/config.cpp
+++ b/src/worker/config.cpp
@@ -1,6 +1,7 @@
 #include "config.h"
 #include "protocol.h"
 #include <algorithm>
+#include <filesystem>
 #include <iostream>
 
 namespace suco::worker {
@@ -61,11 +62,21 @@ Config Config::parse(int argc, char** argv) {
     if (hc_dir_env) {
         config.header_cache_dir = hc_dir_env;
     } else {
+        // HOME is normally unset on Windows (it uses USERPROFILE/LOCALAPPDATA), so the
+        // old "/tmp/..." fallback handed a Windows worker a path that cannot exist.
+        // Try the platform's own home variables, then the platform temp dir.
         const char* home = std::getenv("HOME");
-        if (home) {
+#ifdef _WIN32
+        if (!home) home = std::getenv("LOCALAPPDATA");
+        if (!home) home = std::getenv("USERPROFILE");
+#endif
+        if (home && *home) {
             config.header_cache_dir = std::string(home) + "/.cache/suco/headers";
         } else {
-            config.header_cache_dir = "/tmp/.cache/suco/headers";
+            std::error_code ec;
+            const std::filesystem::path tdir = std::filesystem::temp_directory_path(ec);
+            config.header_cache_dir =
+                (ec ? std::string(".") : tdir.generic_string()) + "/.cache/suco/headers";
         }
     }
 
diff --git a/src/worker/toolchain_manager.cpp b/src/worker/toolchain_manager.cpp
index e0b8930..7048eb3 100644
--- a/src/worker/toolchain_manager.cpp
+++ b/src/worker/toolchain_manager.cpp
@@ -82,7 +82,15 @@ bool ToolchainManager::extract_toolchain(const std::string& hash, const std::str
 
     SUCO_LOG_INFO("Extracting toolchain {} from {}...", hash, archive_path);
 
+    // `-I zstd` is GNU tar syntax. Windows 10/11 ship **bsdtar** (libarchive) as
+    // tar.exe, which rejects -I outright — so a Windows worker failed every toolchain
+    // extraction and could never run a dispatched job at all. bsdtar detects zstd from
+    // the stream itself, so plain -xf is both sufficient and correct there.
+#ifdef _WIN32
+    std::string cmd = "tar -xf \"" + archive_path + "\" -C \"" + tmp_dir + "\"";
+#else
     std::string cmd = "tar -I zstd -xf \"" + archive_path + "\" -C \"" + tmp_dir + "\"";
+#endif
     std::string out_log;
     if (!run_cmd_simple(cmd, out_log)) {
         SUCO_LOG_ERROR("Failed to extract toolchain archive {}. Output: {}", archive_path, out_log);
diff --git a/src/worker/worker.cpp b/src/worker/worker.cpp
index 30cce8b..001c038 100644
--- a/src/worker/worker.cpp
+++ b/src/worker/worker.cpp
@@ -642,7 +642,15 @@ void Worker::run_worker_compile_loop() {
                             std::error_code ec;
                             std::filesystem::create_directories(std::filesystem::path(cache_dir).parent_path(), ec);
                             
-                            std::string temp_archive = "/tmp/suco_tc_recv_" + toolchain_hash + ".tar.zst";
+                            // Use the platform temp dir: "/tmp" does not exist on a
+                            // Windows worker, so this write failed and the toolchain
+                            // was never received. Fall back next to the cache dir if
+                            // the temp dir cannot be determined.
+                            std::error_code tec;
+                            std::filesystem::path tdir = std::filesystem::temp_directory_path(tec);
+                            if (tec) { tec.clear(); tdir = std::filesystem::path(cache_dir).parent_path(); }
+                            std::string temp_archive =
+                                (tdir / ("suco_tc_recv_" + toolchain_hash + ".tar.zst")).string();
                             if (suco::receive_file(download_sock, temp_archive)) {
                                 SUCO_LOG_INFO("Worker successfully received toolchain archive: {}", temp_archive);
                                 ToolchainManager::extract_toolchain(toolchain_hash, temp_archive);