diff --git a/catser/window_manager.py b/catser/window_manager.py
new file mode 100644
index 0000000..d99bd6a
--- /dev/null
+++ b/catser/window_manager.py
@@ -0,0 +1,254 @@
+"""
+Win32 Window Manager for Catser.
+
+Handles native Windows window operations:
+- Locating windows by handle (HWND), title pattern, or process name.
+- Querying exact screen coordinates via GetWindowRect (with DPI awareness).
+- Locating the title bar Close [X] button.
+- Gracefully closing windows using WM_CLOSE or SC_CLOSE messages.
+"""
+
+import ctypes
+from ctypes import wintypes
+import logging
+from dataclasses import dataclass
+from typing import List, Optional, Tuple, Callable
+
+logger = logging.getLogger("catser.windows")
+
+# ==============================================================================
+# Win32 Constants & Structs
+# ==============================================================================
+
+WM_CLOSE = 0x0010
+WM_SYSCOMMAND = 0x0112
+SC_CLOSE = 0xF060
+SC_MINIMIZE = 0xF020
+SW_MINIMIZE = 6
+
+user32 = ctypes.windll.user32
+kernel32 = ctypes.windll.kernel32
+
+# Enable per-monitor DPI awareness so pixel coordinates match high-DPI displays
+try:
+    # PROCESS_PER_MONITOR_DPI_AWARE_V2 = -4
+    ctypes.windll.user32.SetProcessDpiAwarenessContext(ctypes.c_void_p(-4))
+except Exception:
+    try:
+        ctypes.windll.user32.SetProcessDPIAware()
+    except Exception:
+        pass
+
+
+@dataclass
+class WindowInfo:
+    """Represents metadata and geometry of an active Windows desktop window."""
+    hwnd: int
+    title: str
+    process_name: str
+    rect: Tuple[int, int, int, int]  # (left, top, right, bottom)
+    close_button: Tuple[int, int]    # (x, y) coordinates of the [X] close button
+    is_visible: bool
+    is_minimized: bool
+
+    @property
+    def width(self) -> int:
+        return max(0, self.rect[2] - self.rect[0])
+
+    @property
+    def height(self) -> int:
+        return max(0, self.rect[3] - self.rect[1])
+
+
+class WindowManager:
+    """Win32 window query and manipulation utility."""
+
+    @staticmethod
+    def get_window_title(hwnd: int) -> str:
+        """Retrieves the title text of the given window."""
+        length = user32.GetWindowTextLengthW(hwnd)
+        if length == 0:
+            return ""
+        buff = ctypes.create_unicode_buffer(length + 1)
+        user32.GetWindowTextW(hwnd, buff, length + 1)
+        return buff.value
+
+    @staticmethod
+    def get_process_name_for_hwnd(hwnd: int) -> str:
+        """Retrieves the executable process name for the window."""
+        pid = wintypes.DWORD()
+        user32.GetWindowThreadProcessId(hwnd, ctypes.byref(pid))
+        if pid.value == 0:
+            return ""
+
+        # Query process image name via OpenProcess + QueryFullProcessImageNameW
+        PROCESS_QUERY_LIMITED_INFORMATION = 0x1000
+        h_process = kernel32.OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, False, pid.value)
+        if not h_process:
+            return ""
+
+        try:
+            buf_size = wintypes.DWORD(1024)
+            path_buf = ctypes.create_unicode_buffer(1024)
+            if kernel32.QueryFullProcessImageNameW(h_process, 0, path_buf, ctypes.byref(buf_size)):
+                full_path = path_buf.value
+                return full_path.split("\\")[-1].lower()
+        finally:
+            kernel32.CloseHandle(h_process)
+
+        return ""
+
+    @staticmethod
+    def get_window_rect(hwnd: int) -> Optional[Tuple[int, int, int, int]]:
+        """
+        Retrieves the bounding rectangle (left, top, right, bottom) of the window.
+        Returns None if invalid or hidden.
+        """
+        rect = wintypes.RECT()
+        if user32.GetWindowRect(hwnd, ctypes.byref(rect)):
+            return (rect.left, rect.top, rect.right, rect.bottom)
+        return None
+
+    @classmethod
+    def get_close_button_coords(cls, rect: Tuple[int, int, int, int]) -> Tuple[int, int]:
+        """
+        Estimates the screen coordinate of the [X] close button for a window.
+        Standard Windows 10/11 title bar puts the center of [X] approx 24px from right, 16px from top.
+        """
+        left, top, right, bottom = rect
+        # Center of standard Windows close button in title bar
+        close_x = right - 24
+        close_y = top + 16
+
+        # Clamp in case of unusually small windows
+        close_x = max(left + 10, min(right - 5, close_x))
+        close_y = max(top + 5, min(bottom - 5, close_y))
+        return (close_x, close_y)
+
+    @classmethod
+    def get_window_info(cls, hwnd: int) -> Optional[WindowInfo]:
+        """Gathers full WindowInfo for a window handle."""
+        if not user32.IsWindow(hwnd):
+            return None
+
+        is_visible = bool(user32.IsWindowVisible(hwnd))
+        is_minimized = bool(user32.IsIconic(hwnd))
+
+        # Filter out zero-size or invisible windows
+        rect = cls.get_window_rect(hwnd)
+        if not rect:
+            return None
+
+        # Ignore tiny offscreen or hidden utility windows
+        width = rect[2] - rect[0]
+        height = rect[3] - rect[1]
+        if width <= 10 or height <= 10:
+            return None
+
+        title = cls.get_window_title(hwnd)
+        proc_name = cls.get_process_name_for_hwnd(hwnd)
+        close_pos = cls.get_close_button_coords(rect)
+
+        return WindowInfo(
+            hwnd=hwnd,
+            title=title,
+            process_name=proc_name,
+            rect=rect,
+            close_button=close_pos,
+            is_visible=is_visible,
+            is_minimized=is_minimized,
+        )
+
+    @classmethod
+    def get_foreground_window_info(cls) -> Optional[WindowInfo]:
+        """Retrieves info for the current foreground (active) window."""
+        hwnd = user32.GetForegroundWindow()
+        if not hwnd:
+            return None
+        return cls.get_window_info(hwnd)
+
+    @classmethod
+    def find_window_by_match(
+        cls,
+        title_predicate: Optional[Callable[[str], bool]] = None,
+        process_predicate: Optional[Callable[[str], bool]] = None,
+    ) -> Optional[WindowInfo]:
+        """
+        Enumerates top-level desktop windows to find the first matching window.
+        """
+        found_hwnd = None
+
+        WNDENUMPROC = ctypes.WINFUNCTYPE(ctypes.c_bool, wintypes.HWND, wintypes.LPARAM)
+
+        def enum_proc(hwnd, lparam):
+            nonlocal found_hwnd
+            if not user32.IsWindowVisible(hwnd) or user32.IsIconic(hwnd):
+                return True
+
+            title = cls.get_window_title(hwnd)
+            if not title:
+                return True
+
+            if title_predicate and title_predicate(title):
+                found_hwnd = hwnd
+                return False  # Stop enumeration
+
+            if process_predicate:
+                pname = cls.get_process_name_for_hwnd(hwnd)
+                if pname and process_predicate(pname):
+                    found_hwnd = hwnd
+                    return False
+
+            return True
+
+        user32.EnumWindows(WNDENUMPROC(enum_proc), 0)
+
+        if found_hwnd:
+            return cls.get_window_info(found_hwnd)
+        return None
+
+    @classmethod
+    def close_window(cls, hwnd: int) -> bool:
+        """
+        Sends WM_CLOSE and SC_CLOSE to cleanly request the window to close.
+        Returns True if message was successfully posted.
+        """
+        if not user32.IsWindow(hwnd):
+            logger.warning(f"Cannot close invalid window handle: {hwnd}")
+            return False
+
+        logger.info(f"Closing window {hwnd} ('{cls.get_window_title(hwnd)}')")
+        # Send WM_CLOSE
+        res1 = user32.PostMessageW(hwnd, WM_CLOSE, 0, 0)
+        # Also post SC_CLOSE via WM_SYSCOMMAND as a robust secondary signal
+        res2 = user32.PostMessageW(hwnd, WM_SYSCOMMAND, SC_CLOSE, 0)
+        return bool(res1 or res2)
+
+    @classmethod
+    def minimize_window(cls, hwnd: int) -> bool:
+        """Minimizes the window instead of closing it."""
+        if not user32.IsWindow(hwnd):
+            return False
+        return bool(user32.ShowWindow(hwnd, SW_MINIMIZE))
+
+    @staticmethod
+    def get_screen_dimensions() -> Tuple[int, int]:
+        """Returns primary screen width and height in pixels."""
+        SM_CXSCREEN = 0
+        SM_CYSCREEN = 1
+        w = user32.GetSystemMetrics(SM_CXSCREEN)
+        h = user32.GetSystemMetrics(SM_CYSCREEN)
+        return (w, h)
+
+    @staticmethod
+    def get_work_area() -> Tuple[int, int, int, int]:
+        """
+        Returns desktop work area (left, top, right, bottom) excluding the taskbar.
+        """
+        SPI_GETWORKAREA = 0x0030
+        rect = wintypes.RECT()
+        if user32.SystemParametersInfoW(SPI_GETWORKAREA, 0, ctypes.byref(rect), 0):
+            return (rect.left, rect.top, rect.right, rect.bottom)
+        # Fallback to full screen
+        w, h = WindowManager.get_screen_dimensions()
+        return (0, 0, w, h)