diff --git a/App.cmake b/App.cmake
index 4104b2a..fa9e9c8 100644
--- a/App.cmake
+++ b/App.cmake
@@ -9,7 +9,8 @@
 # `docs/CMake API.md` in the JUCE repo for the full list.
 
 if(RNBO_EDITOR_MODE STREQUAL "WEBVIEW")
-  set(_needs_web_browser NEEDS_WEB_BROWSER TRUE)
+  # NEEDS_WEBVIEW2 links the WebView2 SDK on Windows (see WebView2.cmake); ignored elsewhere
+  set(_needs_web_browser NEEDS_WEB_BROWSER TRUE NEEDS_WEBVIEW2 TRUE)
 endif()
 
 juce_add_gui_app(RNBOApp
@@ -54,6 +55,10 @@ if(RNBO_EDITOR_MODE STREQUAL "NATIVE")
   include(${NATIVE_EDITOR_DIR}/CMakeLists.txt)
 elseif(RNBO_EDITOR_MODE STREQUAL "WEBVIEW")
   include(${WEB_EDITOR_DIR}/CMakeLists.txt)
+  if(WIN32)
+    # Enables the WebView2 backend, which WebBrowserComponent needs on Windows for withResourceProvider
+    target_compile_definitions(RNBOApp PUBLIC JUCE_USE_WIN_WEBVIEW2_WITH_STATIC_LINKING=1)
+  endif()
 endif()
 
 if (EXISTS ${RNBO_BINARY_DATA_FILE})
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b542203..f29ce5a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,6 +20,14 @@ mark_as_advanced(RNBO_CLASS_FILE_NAME)
 
 set(RNBO_CLASS_NAME "rnbomatic")
 set(RNBO_CLASS_FILE "${RNBO_EXPORT_DIR}/${RNBO_CLASS_FILE_NAME}")
+if(NOT EXISTS "${RNBO_CLASS_FILE}")
+  message(FATAL_ERROR
+    "RNBO class file not found: ${RNBO_CLASS_FILE}\n"
+    "Export your RNBO patch to ${RNBO_EXPORT_DIR}, and make sure RNBO_CLASS_FILE_NAME "
+    "matches the exported .cpp file name (currently \"${RNBO_CLASS_FILE_NAME}\").\n"
+    "In Windows PowerShell, quote the whole argument so the name isn't split at the period, "
+    "e.g. \"-DRNBO_CLASS_FILE_NAME=my_patch.cpp\"")
+endif()
 set(RNBO_DESCRIPTION_FILE "${RNBO_EXPORT_DIR}/description.json")
 set(RNBO_PRESETS_FILE "${RNBO_EXPORT_DIR}/presets.json")
 set(RNBO_BINARY_DATA_FILE "${RNBO_EXPORT_DIR}/${RNBO_CLASS_NAME}_binary.cpp")
@@ -64,6 +72,10 @@ add_subdirectory(
 # Compile web UI files into the binary — only needed for the WEBVIEW editor.
 if(RNBO_EDITOR_MODE STREQUAL "WEBVIEW")
     add_subdirectory(${WEB_EDITOR_DIR})
+    # Windows also needs the WebView2 SDK, fetched here if it isn't already installed
+    if(WIN32)
+        include(${CMAKE_CURRENT_LIST_DIR}/WebView2.cmake)
+    endif()
 endif()
 
 # Create the correct UI header depending on UI style
diff --git a/CUSTOM_UI.md b/CUSTOM_UI.md
index 0f2e00c..13cc369 100644
--- a/CUSTOM_UI.md
+++ b/CUSTOM_UI.md
@@ -10,7 +10,7 @@ For most people, we recommend starting with the web-based approach.
 
 ## Prerequisites
 
-If you haven't yet followed the setup steps in [README.md](./README.md), you should do so before you follow this tutorial. If you want to follow the guide for building a web-based interface, you will also need to install [Node.js](https://nodejs.org/).
+If you haven't yet followed the setup steps in [README.md](./README.md), you should do so before you follow this tutorial. If you want to follow the guide for building a web-based interface, you will also need to install [Node.js](https://nodejs.org/). On Windows, CMake will also download the Microsoft WebView2 SDK the first time you configure the web UI build; see [Choosing a UI system](./README.md#choosing-a-ui-system) for details.
 
 ## Switching UI
 
@@ -67,6 +67,8 @@ cd build
 cmake .. -DRNBO_CLASS_FILE_NAME=three-param-kink.cpp -DRNBO_EDITOR_MODE=WEBVIEW
 ```
 
+> In Windows PowerShell, quote the class file argument (`"-DRNBO_CLASS_FILE_NAME=three-param-kink.cpp"`), otherwise PowerShell splits it at the period. See [Renaming your export source](./README.md#renaming-your-export-source).
+
 If you look in `src/CustomAudioProcessor.cpp`, you'll see code like this:
 
 ```cpp
diff --git a/Plugin.cmake b/Plugin.cmake
index 8dc0195..227f9d1 100644
--- a/Plugin.cmake
+++ b/Plugin.cmake
@@ -17,7 +17,8 @@ endif()
 # Check the readme at `docs/CMake API.md` in the JUCE repo for the full list.
 
 if(RNBO_EDITOR_MODE STREQUAL "WEBVIEW")
-  set(_needs_web_browser NEEDS_WEB_BROWSER TRUE)
+  # NEEDS_WEBVIEW2 links the WebView2 SDK on Windows (see WebView2.cmake); ignored elsewhere
+  set(_needs_web_browser NEEDS_WEB_BROWSER TRUE NEEDS_WEBVIEW2 TRUE)
 endif()
 
 juce_add_plugin(RNBOAudioPlugin
@@ -65,6 +66,10 @@ if(RNBO_EDITOR_MODE STREQUAL "NATIVE")
   include(${NATIVE_EDITOR_DIR}/CMakeLists.txt)
 elseif(RNBO_EDITOR_MODE STREQUAL "WEBVIEW")
   include(${WEB_EDITOR_DIR}/CMakeLists.txt)
+  if(WIN32)
+    # Enables the WebView2 backend, which WebBrowserComponent needs on Windows for withResourceProvider
+    target_compile_definitions(RNBOAudioPlugin PUBLIC JUCE_USE_WIN_WEBVIEW2_WITH_STATIC_LINKING=1)
+  endif()
 endif()
 
 if (EXISTS ${RNBO_BINARY_DATA_FILE})
diff --git a/README.md b/README.md
index a1fada3..3a294ae 100644
--- a/README.md
+++ b/README.md
@@ -125,6 +125,8 @@ By default, the build script looks for a RNBO export in the `export` folder name
 cmake -DRNBO_CLASS_FILE_NAME=slime_sound.cpp -G Ninja ..
 ```
 
+**Windows PowerShell:** PowerShell splits unquoted arguments like this one at the period, so CMake only sees `slime_sound`. Wrap the whole argument in quotes: `"-DRNBO_CLASS_FILE_NAME=slime_sound.cpp"`.
+
 #### Choosing a UI system
 
 RNBO provides a default interface for audio plugins, which simply creates a slider for each parameter in your RNBO patch. If you want to create a custom interface, you can configure CMake to use a different interface system.
@@ -141,6 +143,12 @@ The second uses a WebBrowserComponent to build a UI using HTML/CSS/JS.
 cmake -DRNBO_EDITOR_MODE=WEBVIEW ..
 ```
 
+**Windows:** the WEBVIEW editor uses Microsoft's WebView2, which needs the WebView2 SDK at build time. If the SDK isn't already installed through NuGet, CMake downloads it (about 9 MB) into `build/_deps/webview2` the first time you configure. To use a copy you already have, for example when building offline, point CMake at the directory containing the `Microsoft.Web.WebView2.*` package folder:
+
+```sh
+cmake -DRNBO_EDITOR_MODE=WEBVIEW -DJUCE_WEBVIEW2_PACKAGE_LOCATION=C:/path/to/packages ..
+```
+
 By default, `NATIVE` sources its C++ files from `src/nativeui` and `WEBVIEW` sources its files from `src/webui`. If you want to supply your own implementation — for example, to keep your custom UI in a separate directory or a separate repository — you can override either path at configure time:
 
 ```sh
diff --git a/WebView2.cmake b/WebView2.cmake
new file mode 100644
index 0000000..0b5f597
--- /dev/null
+++ b/WebView2.cmake
@@ -0,0 +1,48 @@
+# On Windows, the WEBVIEW editor needs the Microsoft WebView2 SDK. JUCE looks for it in the local
+# NuGet package folder, or in JUCE_WEBVIEW2_PACKAGE_LOCATION if that is set. If neither has it, we
+# download the NuGet package into the build tree and point JUCE at it.
+#
+# To use your own copy (e.g. for offline builds), configure with
+#   cmake -DJUCE_WEBVIEW2_PACKAGE_LOCATION=<dir containing Microsoft.Web.WebView2.*> ..
+
+set(WEBVIEW2_VERSION "1.0.3485.44")
+set(WEBVIEW2_SHA256 "bc09150b179246ac90189649b13be8e6b11b3ac200e817e18df106e1f3cf489e")
+
+file(GLOB _webview2_nuget_packages "$ENV{USERPROFILE}/AppData/Local/PackageManagement/NuGet/Packages/*Microsoft.Web.WebView2*")
+
+if(JUCE_WEBVIEW2_PACKAGE_LOCATION)
+  message(STATUS "Using WebView2 SDK from ${JUCE_WEBVIEW2_PACKAGE_LOCATION}")
+elseif(_webview2_nuget_packages)
+  message(STATUS "Using WebView2 SDK from the local NuGet package folder")
+else()
+  set(_webview2_root "${CMAKE_BINARY_DIR}/_deps/webview2")
+  set(_webview2_dir "${_webview2_root}/Microsoft.Web.WebView2.${WEBVIEW2_VERSION}")
+
+  if(NOT EXISTS "${_webview2_dir}/build/native/include/WebView2.h")
+    set(_webview2_nupkg "${_webview2_root}/Microsoft.Web.WebView2.${WEBVIEW2_VERSION}.nupkg")
+    message(STATUS "Downloading WebView2 SDK ${WEBVIEW2_VERSION}")
+
+    file(DOWNLOAD
+      "https://www.nuget.org/api/v2/package/Microsoft.Web.WebView2/${WEBVIEW2_VERSION}"
+      "${_webview2_nupkg}"
+      EXPECTED_HASH SHA256=${WEBVIEW2_SHA256}
+      STATUS _webview2_status)
+
+    list(GET _webview2_status 0 _webview2_status_code)
+    if(NOT _webview2_status_code EQUAL 0)
+      list(GET _webview2_status 1 _webview2_status_message)
+      message(FATAL_ERROR
+        "Failed to download the WebView2 SDK: ${_webview2_status_message}\n"
+        "Install it manually from a PowerShell prompt:\n"
+        "> Register-PackageSource -provider NuGet -name nugetRepository -location https://www.nuget.org/api/v2\n"
+        "> Install-Package Microsoft.Web.WebView2 -Scope CurrentUser -RequiredVersion ${WEBVIEW2_VERSION} -Source nugetRepository\n"
+        "or pass -DJUCE_WEBVIEW2_PACKAGE_LOCATION=<dir> pointing at an existing copy.")
+    endif()
+
+    file(ARCHIVE_EXTRACT INPUT "${_webview2_nupkg}" DESTINATION "${_webview2_dir}")
+    file(REMOVE "${_webview2_nupkg}")
+  endif()
+
+  set(JUCE_WEBVIEW2_PACKAGE_LOCATION "${_webview2_root}")
+  message(STATUS "Using WebView2 SDK from ${_webview2_dir}")
+endif()