diff --git a/build/scripts/build_windows.py b/build/scripts/build_windows.py
index 87df6e9..b0cdbba 100644
--- a/build/scripts/build_windows.py
+++ b/build/scripts/build_windows.py
@@ -123,13 +123,21 @@ class WindowsBuilder:
         """
         print("\n📦 Creating MSI installer with WiX...")
 
-        # Check if WiX is installed
+        # Check if WiX is installed (try PATH first, then default location)
         heat_exe = shutil.which("heat.exe")
         candle_exe = shutil.which("candle.exe")
         light_exe = shutil.which("light.exe")
 
+        # Fallback to default WiX installation location
+        if not candle_exe:
+            default_wix = Path("C:\\Program Files (x86)\\WiX Toolset v3.14\\bin")
+            if default_wix.exists():
+                heat_exe = str(default_wix / "heat.exe")
+                candle_exe = str(default_wix / "candle.exe")
+                light_exe = str(default_wix / "light.exe")
+
         if not all([heat_exe, candle_exe, light_exe]):
-            print("⚠️  WiX Toolset not found in PATH")
+            print("⚠️  WiX Toolset not found in PATH or default location")
             print("  Install from: https://wixtoolset.org/releases/")
             print("  Or use: choco install wixtoolset")
             return False
@@ -142,9 +150,10 @@ class WindowsBuilder:
         wix_obj = self.build_dir / "WebDropBridge.wixobj"
         msi_output = self.dist_dir / f"WebDropBridge-{self.version}-Setup.msi"
 
-        # Run candle (compiler)
+        # Run candle (compiler) - pass preprocessor variables
         candle_cmd = [
             str(candle_exe),
+            f"-dDistDir={self.dist_dir}",
             "-o",
             str(wix_obj),
             str(self.build_dir / "WebDropBridge.wxs"),