diff --git a/src/vs/workbench/contrib/notebook/browser/view/renderers/backLayerWebView.ts b/src/vs/workbench/contrib/notebook/browser/view/renderers/backLayerWebView.ts
index a0ede8f32a7..3c952547e78 100644
--- a/src/vs/workbench/contrib/notebook/browser/view/renderers/backLayerWebView.ts
+++ b/src/vs/workbench/contrib/notebook/browser/view/renderers/backLayerWebView.ts
@@ -513,10 +513,10 @@ export class BackLayerWebView<T extends ICommonCellInfo> extends Themable {
 		return !!this.webview;
 	}
 
-	createWebview(codeWindow: CodeWindow): Promise<void> {
+	createWebview(targetWindow: CodeWindow): Promise<void> {
 		const baseUrl = this.asWebviewUri(this.getNotebookBaseUri(), undefined);
 		const htmlContent = this.generateContent(baseUrl.toString());
-		return this._initialize(htmlContent, codeWindow);
+		return this._initialize(htmlContent, targetWindow);
 	}
 
 	private getNotebookBaseUri() {
@@ -551,16 +551,16 @@ export class BackLayerWebView<T extends ICommonCellInfo> extends Themable {
 		];
 	}
 
-	private async _initialize(content: string, codeWindow: CodeWindow): Promise<void> {
+	private async _initialize(content: string, targetWindow: CodeWindow): Promise<void> {
 		if (!getWindow(this.element).document.body.contains(this.element)) {
 			throw new Error('Element is already detached from the DOM tree');
 		}
 
 		this.webview = this._createInset(this.webviewService, content);
-		this.webview.mountTo(this.element, codeWindow);
+		this.webview.mountTo(this.element, targetWindow);
 		this._register(this.webview);
 
-		this._register(new WebviewWindowDragMonitor(codeWindow, () => this.webview));
+		this._register(new WebviewWindowDragMonitor(targetWindow, () => this.webview));
 
 		const initializePromise = new DeferredPromise<void>();
 
diff --git a/src/vs/workbench/contrib/webview/browser/overlayWebview.ts b/src/vs/workbench/contrib/webview/browser/overlayWebview.ts
index be8c3037c2a..a5cfe2c7e89 100644
--- a/src/vs/workbench/contrib/webview/browser/overlayWebview.ts
+++ b/src/vs/workbench/contrib/webview/browser/overlayWebview.ts
@@ -3,10 +3,10 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { Dimension } from 'vs/base/browser/dom';
+import { Dimension, getWindowById } from 'vs/base/browser/dom';
 import { FastDomNode } from 'vs/base/browser/fastDomNode';
 import { IMouseWheelEvent } from 'vs/base/browser/mouseEvent';
-import { CodeWindow } from 'vs/base/browser/window';
+import { CodeWindow, mainWindow } from 'vs/base/browser/window';
 import { Emitter } from 'vs/base/common/event';
 import { Disposable, DisposableStore, MutableDisposable } from 'vs/base/common/lifecycle';
 import { URI } from 'vs/base/common/uri';
@@ -36,7 +36,9 @@ export class OverlayWebview extends Disposable implements IOverlayWebview {
 	private _options: WebviewOptions;
 
 	private _owner: any = undefined;
-	public _codeWindow: CodeWindow | undefined = undefined;
+
+	private _windowId: number | undefined = undefined;
+	private get window() { return typeof this._windowId === 'number' ? getWindowById(this._windowId)?.window : undefined; }
 
 	private readonly _scopedContextKeyService = this._register(new MutableDisposable<IScopedContextKeyService>());
 	private _findWidgetVisible: IContextKey<boolean> | undefined;
@@ -105,21 +107,20 @@ export class OverlayWebview extends Disposable implements IOverlayWebview {
 
 			// Webviews cannot be reparented in the dom as it will destroy their contents.
 			// Mount them to a high level node to avoid this.
-			const layoutContainer = this._codeWindow ? this._layoutService.getContainer(this._codeWindow) : this._layoutService.mainContainer;
-			layoutContainer.appendChild(node);
+			this._layoutService.getContainer(this.window ?? mainWindow).appendChild(node);
 		}
 
 		return this._container.domNode;
 	}
 
-	public claim(owner: any, codeWindow: CodeWindow, scopedContextKeyService: IContextKeyService | undefined) {
+	public claim(owner: any, targetWindow: CodeWindow, scopedContextKeyService: IContextKeyService | undefined) {
 		if (this._isDisposed) {
 			return;
 		}
 
 		const oldOwner = this._owner;
 
-		if (this._codeWindow && this._codeWindow?.vscodeWindowId !== codeWindow.vscodeWindowId) {
+		if (this._windowId !== targetWindow.vscodeWindowId) {
 			// moving to a new window
 			this.release(oldOwner);
 			this._container?.domNode.remove();
@@ -127,8 +128,8 @@ export class OverlayWebview extends Disposable implements IOverlayWebview {
 		}
 
 		this._owner = owner;
-		this._codeWindow = codeWindow;
-		this._show(codeWindow);
+		this._windowId = targetWindow.vscodeWindowId;
+		this._show(targetWindow);
 
 		if (oldOwner !== owner) {
 			const contextKeyService = (scopedContextKeyService || this._baseContextKeyService);
@@ -195,7 +196,7 @@ export class OverlayWebview extends Disposable implements IOverlayWebview {
 		}
 	}
 
-	private _show(codeWindow: CodeWindow) {
+	private _show(targetWindow: CodeWindow) {
 		if (this._isDisposed) {
 			throw new Error('OverlayWebview is disposed');
 		}
@@ -207,7 +208,7 @@ export class OverlayWebview extends Disposable implements IOverlayWebview {
 				title: this._title,
 				options: this._options,
 				contentOptions: this._contentOptions,
-				extension: this.extension
+				extension: this.extension,
 			});
 			this._webview.value = webview;
 			webview.state = this._state;
@@ -226,7 +227,7 @@ export class OverlayWebview extends Disposable implements IOverlayWebview {
 
 			this._findWidgetEnabled?.set(!!this.options.enableFindWidget);
 
-			webview.mountTo(this.container, codeWindow);
+			webview.mountTo(this.container, targetWindow);
 
 			// Forward events from inner webview to outer listeners
 			this._webviewEvents.clear();
diff --git a/src/vs/workbench/contrib/webview/browser/webview.ts b/src/vs/workbench/contrib/webview/browser/webview.ts
index 693d6dd9f03..14e925969a1 100644
--- a/src/vs/workbench/contrib/webview/browser/webview.ts
+++ b/src/vs/workbench/contrib/webview/browser/webview.ts
@@ -277,7 +277,7 @@ export interface IWebviewElement extends IWebview {
 	 *
 	 * @param parent Element to append the webview to.
 	 */
-	mountTo(parent: HTMLElement, codeWindow: CodeWindow): void;
+	mountTo(parent: HTMLElement, targetWindow: CodeWindow): void;
 }
 
 /**
@@ -307,7 +307,7 @@ export interface IOverlayWebview extends IWebview {
 	 * @param claimant Identifier for the object claiming the webview.
 	 *   This must match the `claimant` passed to {@link IOverlayWebview.release}.
 	 */
-	claim(claimant: any, codeWindow: CodeWindow, scopedContextKeyService: IContextKeyService | undefined): void;
+	claim(claimant: any, targetWindow: CodeWindow, scopedContextKeyService: IContextKeyService | undefined): void;
 
 	/**
 	 * Release ownership of the webview.
diff --git a/src/vs/workbench/contrib/webview/browser/webviewElement.ts b/src/vs/workbench/contrib/webview/browser/webviewElement.ts
index 8207987cbc5..0d950ccf6fa 100644
--- a/src/vs/workbench/contrib/webview/browser/webviewElement.ts
+++ b/src/vs/workbench/contrib/webview/browser/webviewElement.ts
@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { isFirefox } from 'vs/base/browser/browser';
-import { addDisposableListener, EventType } from 'vs/base/browser/dom';
+import { addDisposableListener, EventType, getWindowById } from 'vs/base/browser/dom';
 import { IMouseWheelEvent } from 'vs/base/browser/mouseEvent';
 import { promiseWithResolvers, ThrottledDelayer } from 'vs/base/common/async';
 import { streamToBuffer, VSBufferReadableStream } from 'vs/base/common/buffer';
@@ -88,7 +88,8 @@ export class WebviewElement extends Disposable implements IWebview, WebviewFindD
 	 */
 	public readonly origin: string;
 
-	private _codeWindow?: CodeWindow;
+	private _windowId: number | undefined = undefined;
+	private get window() { return typeof this._windowId === 'number' ? getWindowById(this._windowId)?.window : undefined; }
 
 	private _encodedWebviewOriginPromise?: Promise<string>;
 	private _encodedWebviewOrigin: string | undefined;
@@ -106,11 +107,11 @@ export class WebviewElement extends Disposable implements IWebview, WebviewFindD
 			return false;
 		}
 		// code window is only available after the webview is mounted.
-		if (!this._codeWindow) {
+		if (!this.window) {
 			return false;
 		}
 
-		if (this._codeWindow.document.activeElement && this._codeWindow.document.activeElement !== this.element) {
+		if (this.window.document.activeElement && this.window.document.activeElement !== this.element) {
 			// looks like https://github.com/microsoft/vscode/issues/132641
 			// where the focus is actually not in the `<iframe>`
 			return false;
@@ -412,7 +413,7 @@ export class WebviewElement extends Disposable implements IWebview, WebviewFindD
 		return element;
 	}
 
-	private _initElement(encodedWebviewOrigin: string, extension: WebviewExtensionDescription | undefined, options: WebviewOptions, codeWindow: CodeWindow) {
+	private _initElement(encodedWebviewOrigin: string, extension: WebviewExtensionDescription | undefined, options: WebviewOptions, targetWindow: CodeWindow) {
 		// The extensionId and purpose in the URL are used for filtering in js-debug:
 		const params: { [key: string]: string } = {
 			id: this.id,
@@ -421,7 +422,7 @@ export class WebviewElement extends Disposable implements IWebview, WebviewFindD
 			extensionId: extension?.id.value ?? '',
 			platform: this.platform,
 			'vscode-resource-base-authority': webviewRootResourceAuthority,
-			parentOrigin: codeWindow.origin,
+			parentOrigin: targetWindow.origin,
 		};
 
 		if (this._options.disableServiceWorker) {
@@ -446,19 +447,19 @@ export class WebviewElement extends Disposable implements IWebview, WebviewFindD
 		this.element!.setAttribute('src', `${this.webviewContentEndpoint(encodedWebviewOrigin)}/${fileName}?${queryString}`);
 	}
 
-	public mountTo(element: HTMLElement, codeWindow: CodeWindow) {
+	public mountTo(element: HTMLElement, targetWindow: CodeWindow) {
 		if (!this.element) {
 			return;
 		}
 
-		this._codeWindow = codeWindow;
-		this._encodedWebviewOriginPromise = parentOriginHash(codeWindow.origin, this.origin).then(id => this._encodedWebviewOrigin = id);
+		this._windowId = targetWindow.vscodeWindowId;
+		this._encodedWebviewOriginPromise = parentOriginHash(targetWindow.origin, this.origin).then(id => this._encodedWebviewOrigin = id);
 		this._encodedWebviewOriginPromise.then(encodedWebviewOrigin => {
 			if (!this._disposed) {
-				this._initElement(encodedWebviewOrigin, this.extension, this._options, codeWindow);
+				this._initElement(encodedWebviewOrigin, this.extension, this._options, targetWindow);
 			}
 		});
-		this._registerMessageHandler(codeWindow);
+		this._registerMessageHandler(targetWindow);
 
 		if (this._webviewFindWidget) {
 			element.appendChild(this._webviewFindWidget.getDomNode());
@@ -470,7 +471,7 @@ export class WebviewElement extends Disposable implements IWebview, WebviewFindD
 			}));
 		}
 
-		for (const node of [element, codeWindow]) {
+		for (const node of [element, targetWindow]) {
 			this._register(addDisposableListener(node, EventType.DRAG_END, () => {
 				this._stopBlockingIframeDragEvents();
 			}));
@@ -481,8 +482,8 @@ export class WebviewElement extends Disposable implements IWebview, WebviewFindD
 		element.appendChild(this.element);
 	}
 
-	private _registerMessageHandler(codeWindow: CodeWindow) {
-		const subscription = this._register(addDisposableListener(codeWindow, 'message', (e: MessageEvent) => {
+	private _registerMessageHandler(targetWindow: CodeWindow) {
+		const subscription = this._register(addDisposableListener(targetWindow, 'message', (e: MessageEvent) => {
 			if (!this._encodedWebviewOrigin || e?.data?.target !== this.id) {
 				return;
 			}
@@ -693,7 +694,7 @@ export class WebviewElement extends Disposable implements IWebview, WebviewFindD
 			get: () => this.element,
 		});
 		// And re-dispatch
-		this._codeWindow?.dispatchEvent(emulatedKeyboardEvent);
+		this.window?.dispatchEvent(emulatedKeyboardEvent);
 	}
 
 	windowDidDragStart(): void {
@@ -835,7 +836,7 @@ export class WebviewElement extends Disposable implements IWebview, WebviewFindD
 				return;
 			}
 
-			if (this._codeWindow?.document.activeElement && this._codeWindow.document.activeElement !== this.element && this._codeWindow.document.activeElement?.tagName !== 'BODY') {
+			if (this.window?.document.activeElement && this.window.document.activeElement !== this.element && this.window.document.activeElement?.tagName !== 'BODY') {
 				return;
 			}
 
diff --git a/src/vs/workbench/contrib/webview/browser/webviewWindowDragMonitor.ts b/src/vs/workbench/contrib/webview/browser/webviewWindowDragMonitor.ts
index df03e2c31cc..e4dc5eaf0e9 100644
--- a/src/vs/workbench/contrib/webview/browser/webviewWindowDragMonitor.ts
+++ b/src/vs/workbench/contrib/webview/browser/webviewWindowDragMonitor.ts
@@ -15,10 +15,10 @@ import { IWebview } from 'vs/workbench/contrib/webview/browser/webview';
  * event so it can handle editor element drag drop.
  */
 export class WebviewWindowDragMonitor extends Disposable {
-	constructor(codeWindow: CodeWindow, getWebview: () => IWebview | undefined) {
+	constructor(targetWindow: CodeWindow, getWebview: () => IWebview | undefined) {
 		super();
 
-		this._register(DOM.addDisposableListener(codeWindow, DOM.EventType.DRAG_START, () => {
+		this._register(DOM.addDisposableListener(targetWindow, DOM.EventType.DRAG_START, () => {
 			getWebview()?.windowDidDragStart();
 		}));
 
@@ -26,8 +26,8 @@ export class WebviewWindowDragMonitor extends Disposable {
 			getWebview()?.windowDidDragEnd();
 		};
 
-		this._register(DOM.addDisposableListener(codeWindow, DOM.EventType.DRAG_END, onDragEnd));
-		this._register(DOM.addDisposableListener(codeWindow, DOM.EventType.MOUSE_MOVE, currentEvent => {
+		this._register(DOM.addDisposableListener(targetWindow, DOM.EventType.DRAG_END, onDragEnd));
+		this._register(DOM.addDisposableListener(targetWindow, DOM.EventType.MOUSE_MOVE, currentEvent => {
 			if (currentEvent.buttons === 0) {
 				onDragEnd();
 			}