I am looking for a browser extension that can play YouTube videos faster than x2 in the browser, and if possible, work with Google Chrome and Windows 7.
You could use MySpeed (a paid product - I'm not affiliated with it in any way). It integrates automatically with all browsers, although you would have to initially install it via a windows installer.
This will then do EXACTLY what you've asked for:
- play YouTube videos,
- faster than x2,
- in the browser, and
- work with Google Chrome and Windows 7