Windows Shopify CLI 3.0 - An error occured while installing ffi

I've installed Shopify CLI 3.0 on Windows from npm, and I'm getting the following error when I run shopify theme dev --store=...:

An error occurred while installing ffi (1.15.5), and Bundler cannot continue.

In Gemfile:
  listen was resolved to 3.7.1, which depends on
    rb-inotify was resolved to 0.10.1, which depends on
      ffi
Fetching

I've tried re-ininstalling Ruby, but that didn't fix the problem.

Solution

I had the same problem. I removed and reinstalled Ruby and now it's fine. The difference was when I first installed it, I installed to C:\Program Files. I saw some errors relating to the path. When I re-installed Ruby I left it at the default directory of C:\Ruby32-x64\ and now everything works OK.