Here's a few alternatives reflecting my own prefences (usually aesthetic).
TreeSize Free - alternative to WinDirStat.
Intype - simple text editor.
Disconnect - Browser extension for anti-tracking.
That's it.
Everyone pretty much answered your questions already, but I wanted to mention that I like inType (http://inotai.com/intype/) as an editor in Windows. I stopped doing any Ruby dev work in Windows though, my laptop is running linux now & I have a VM running linux on my work machine using Virtualbox. It makes life a lot easier when it comes to using gems.