Update README.md

Author: LiangliangNan

README.md

@@ -37,8 +37,10 @@ There are many options to build AdTree. Choose one of the following (or whatever
 
 - Option 1: Use any IDE that can directly handle CMakeLists files to open the `CMakeLists.txt` in the root directory 
 of AdTree. Then you should have obtained a usable project and just build. I recommend using
- [CLion](https://www.jetbrains.com/clion/) or [QtCreator](https://www.qt.io/product).
-- Option 2: Use CMake to generate project files for your IDE. Then load the project to your IDE and build.
+ [CLion](https://www.jetbrains.com/clion/) or [QtCreator](https://www.qt.io/product). For Windows users: your IDE must be set for `x64`.
+ 
+- Option 2: Use CMake to generate project files for your IDE. Then load the project to your IDE and build. For Windows users: your IDE must be set for `x64`.
+
 - Option 3: Use CMake to generate Makefiles and then build.
   - on Linux or macOS:
     ```