Software development products for Windows, especially professionally-produced ones, tend to be expensive, complex, large, slow, and difficult to learn. Thin Basic is, thankfully, none of these.
The language syntax is not difficult to pick up, although to be fair it's nowhere near as similar to Basic as the product's name would have you believe. Maybe that's why the IDE, or Integrated Development Environment, is actually called Thin Air rather than Thin Basic. Or maybe its developers just liked the name.
Anyhow, if you want to get started writing programs for Windows, Thin Basic (or Thin Air if you prefer) is a great place to start. The download is a very modest 12 MB, the product is entirely free, and it comes with loads of free example scripts that are ready to run. The one shown below is actually a full-blown web browser and, in the highlighted line, you can see how I've changed the text on the "back" button.
Thin Basic is an interpreted language. As soon as you press F5, the program runs. There's no delay while any compilation takes place, which keeps the development process fast. It does, though, mean that you can't distribute your finished programs to people who don't also have Thin Basic.
From my brief foray, I have to admit that the whole product seems very well put together, and was reliable during my testing. And according to Virus Total, there are no nasties lurking within it.
You can download the product from www.thinbasic.com. It should run on Windows XP and above. The web site also has loads of other scripts that you can download, in addition to the ones that are installed alongside the IDE.