diff --git a/build.jai b/build.jai
index f7bbd97..b214d5c 100644
--- a/build.jai
+++ b/build.jai
@@ -15,22 +15,7 @@
     options := get_build_options(w);
     options.output_executable_name = "singbox_tray";
     
-    // Copy libcurl.dll from compiler modules to output directory
-    for options.import_path {
-        dll_path := tprint("%Curl/windows/lib/libcurl.dll", it);
-        if file_exists(dll_path) {
-            dest_path := "libcurl.dll";
-            if options.output_path {
-                dest_path = tprint("%/libcurl.dll", options.output_path);
-            }
-            if copy_file(dll_path, dest_path) {
-                print("Build: Successfully copied libcurl.dll to %\n", dest_path);
-            } else {
-                print("Build Warning: Could not copy libcurl.dll to %\n", dest_path);
-            }
-            break;
-        }
-    }
+    // No longer need to copy libcurl.dll since we use native Windows WinINet API.
 
     // options.additional_linker_arguments is a slice, so copy it to a dynamic array, append, and assign back
     new_args: [..] string;
diff --git a/cache.db b/cache.db
index 22c4f98..7167119 100644
Binary files a/cache.db and b/cache.db differ
diff --git a/singbox_tray_plan.md b/singbox_tray_plan.md
index c68a93b..49b8f7f 100644
--- a/singbox_tray_plan.md
+++ b/singbox_tray_plan.md
@@ -12,7 +12,7 @@ graph TD
     B -->|Right Click| C[Context Menu]
     C -->|Set URL| D[Custom Edit Dialog]
     C -->|Start/Stop| E[Process Manager: sing-box.exe]
-    C -->|Update Now| F[Auto-Update Loop: libcurl]
+    C -->|Update Now| F[Auto-Update Loop: WinINet]
     C -->|Exit| G[Shutdown & Cleanup]
     F -->|Timer/Thread| F
 ```
@@ -35,7 +35,7 @@ To avoid needing an external resource compiler (`.rc`) or complex UI libraries,
 - **Behavior**: Block interactions with other menus, read the edit text on OK, write it to a `url.txt` file, and trigger an immediate config update.
 
 ### C. Config Downloader (Auto-Update Engine)
-- **Curl Library**: Use the standard `Curl` module to perform HTTP requests.
+- **Downloader**: Use the Windows WinINet API to perform HTTP/HTTPS requests.
 - **Storage**: Save the downloaded JSON content to `config.json` in the same directory as the executable.
 - **Auto-Update Thread**: Spawn a background thread (using `Thread` module) that sleeps for a set interval (e.g., 1 hour), then downloads the URL. If the file content changes, it updates `config.json` and restarts the `sing-box` process if it was running.
 
@@ -49,7 +49,7 @@ To avoid needing an external resource compiler (`.rc`) or complex UI libraries,
 
 1. **`main.jai`**: Core application entry point, hidden window loop, tray icon management.
 2. **`dialog.jai`**: Edit-box dialog for config URL input.
-3. **`updater.jai`**: Libcurl wrapper and background auto-update thread.
+3. **`updater.jai`**: WinINet HTTP/HTTPS client and background auto-update thread.
 4. **`build.jai`**: Jai build script (metaprogram) to compile the app without standard console window popup (using `-subsystem windows`).
 
 ## 4. Key Questions & Decisions
diff --git a/updater.jai b/updater.jai
index b7b3e2c..f5a8615 100644
--- a/updater.jai
+++ b/updater.jai
@@ -1,5 +1,4 @@
 #import "Basic";
-#import "Curl";
 #import "File";
 #import "Thread";
 #import "Windows";
@@ -12,44 +11,65 @@ Updater_Thread_Data :: struct {
     stop_event: HANDLE;
 }
 
-write_callback :: (ptr: *u8, size: u64, nmemb: u64, userdata: *void) -> u64 #c_call {
-    builder := cast(*String_Builder) userdata;
-    push_context {
-        append(builder, ptr, xx nmemb);
-    }
-    return nmemb;
-}
-
 download_url :: (url: string) -> string, bool, string {
-    curl := curl_easy_init();
-    if !curl return "", false, "Failed to initialize Curl";
-    defer curl_easy_cleanup(curl);
+    hInternet := InternetOpenW(
+        utf8_to_wide("SingboxTrayUpdater"),
+        INTERNET_OPEN_TYPE_PRECONFIG,
+        null,
+        null,
+        0
+    );
+    if !hInternet {
+        return "", false, "Failed to initialize WinINet session";
+    }
+    defer InternetCloseHandle(hInternet);
 
-    curl_easy_setopt(curl, .URL, temp_c_string(url));
-    curl_easy_setopt(curl, .FOLLOWLOCATION, 1);
-    curl_easy_setopt(curl, .TIMEOUT, 30);
+    flags: DWORD = INTERNET_FLAG_RELOAD | INTERNET_FLAG_NO_CACHE_WRITE;
+    if starts_with(url, "https") {
+        flags |= INTERNET_FLAG_SECURE;
+    }
 
-    // Disable SSL verification to prevent issues with missing CA cert bundles on Windows
-    curl_easy_setopt(curl, .SSL_VERIFYPEER, 0);
-    curl_easy_setopt(curl, .SSL_VERIFYHOST, 0);
+    hUrl := InternetOpenUrlW(
+        hInternet,
+        utf8_to_wide(url),
+        null,
+        0,
+        flags,
+        0
+    );
+    if !hUrl {
+        err := GetLastError();
+        return "", false, tprint("Failed to open URL (Win32 Error: %)", err);
+    }
+    defer InternetCloseHandle(hUrl);
+
+    // Query response code
+    response_code: DWORD;
+    response_code_size: DWORD = size_of(type_of(response_code));
+    if HttpQueryInfoW(hUrl, HTTP_QUERY_STATUS_CODE | HTTP_QUERY_FLAG_NUMBER, *response_code, *response_code_size, null) {
+        if response_code != 200 {
+            return "", false, tprint("HTTP request failed with status code %", response_code);
+        }
+    } else {
+        err := GetLastError();
+        return "", false, tprint("Failed to query HTTP status code (Win32 Error: %)", err);
+    }
 
     builder: String_Builder;
     defer free_buffers(*builder);
 
-    curl_easy_setopt(curl, .WRITEFUNCTION, write_callback);
-    curl_easy_setopt(curl, .WRITEDATA, *builder);
-
-    curl_code := curl_easy_perform(curl);
-    if curl_code != .OK {
-        err_msg := tprint("Curl perform failed: %", to_string(curl_easy_strerror(curl_code)));
-        return "", false, err_msg;
-    }
-
-    response_code: int;
-    curl_easy_getinfo(curl, .RESPONSE_CODE, *response_code);
-    if response_code != 200 {
-        err_msg := tprint("HTTP request failed with status code %", response_code);
-        return "", false, err_msg;
+    buffer: [4096] u8;
+    bytes_read: DWORD;
+    while true {
+        ok := InternetReadFile(hUrl, buffer.data, xx buffer.count, *bytes_read);
+        if !ok {
+            err := GetLastError();
+            return "", false, tprint("Error reading from URL (Win32 Error: %)", err);
+        }
+        if bytes_read == 0 {
+            break;
+        }
+        append(*builder, buffer.data, xx bytes_read);
     }
 
     return builder_to_string(*builder), true, "";
diff --git a/win32.jai b/win32.jai
index bb835b7..4c62375 100644
--- a/win32.jai
+++ b/win32.jai
@@ -153,6 +153,52 @@ RegCloseKey :: (hKey: HKEY) -> LSTATUS #foreign advapi32;
 
 InternetSetOptionW :: (hInternet: HANDLE, dwOption: DWORD, lpBuffer: *void, dwBufferLength: DWORD) -> BOOL #foreign wininet;
 
+HINTERNET :: *void;
+
+INTERNET_OPEN_TYPE_PRECONFIG :: 0;
+INTERNET_FLAG_RELOAD         :: 0x80000000;
+INTERNET_FLAG_SECURE         :: 0x00800000;
+INTERNET_FLAG_NO_CACHE_WRITE :: 0x04000000;
+
+HTTP_QUERY_STATUS_CODE       :: 19;
+HTTP_QUERY_FLAG_NUMBER       :: 0x20000000;
+
+InternetOpenW :: (
+    lpszAgent: LPCWSTR,
+    dwAccessType: DWORD,
+    lpszProxy: LPCWSTR,
+    lpszProxyBypass: LPCWSTR,
+    dwFlags: DWORD
+) -> HINTERNET #foreign wininet;
+
+InternetOpenUrlW :: (
+    hInternet: HINTERNET,
+    lpszUrl: LPCWSTR,
+    lpszHeaders: LPCWSTR,
+    dwHeadersLength: DWORD,
+    dwFlags: DWORD,
+    dwContext: u64
+) -> HINTERNET #foreign wininet;
+
+InternetReadFile :: (
+    hFile: HINTERNET,
+    lpBuffer: *void,
+    dwNumberOfBytesToRead: DWORD,
+    lpdwNumberOfBytesRead: *DWORD
+) -> BOOL #foreign wininet;
+
+InternetCloseHandle :: (
+    hInternet: HINTERNET
+) -> BOOL #foreign wininet;
+
+HttpQueryInfoW :: (
+    hRequest: HINTERNET,
+    dwInfoLevel: DWORD,
+    lpBuffer: *void,
+    lpdwBufferLength: *DWORD,
+    lpdwIndex: *DWORD
+) -> BOOL #foreign wininet;
+
 wcslen :: (str: *u16) -> int {
     len := 0;
     while str[len] != 0 {