Microsoft shell scripting language, "DOS" batch language, assembly language (if *debug is available at the cmd prompt. Yes folks, debug can be used to create small assembly language programs!) and Visual Basic (scripting).
And html (HyperText Markup Language) -- is also a language proper. You only need a browser to run it -- so since a browser comes with the OS, I'd say it qualifies as a "available by default" language.
Wow - that's 5 already, and I might have missed some.
If Microsoft Office came installed on you PC, you could argue that SQL (via MS Access in Office) is also avail. by default.
*Working with debug at the prompt is how I got started in programming, 'till I got so fed up with assembly language limits, and a friend urged me to try C, so I broke down and bought Turbo C. Man, that was significant moment in my coding history....
C/C++ and similar high-level languages are not available by default, you generally need to install a compiler of some kind to translate the human-readable language into machine code (what's inside an *.EXE file so the OS can run it).
If you're running Unix/Lynix, then C, Pearl and a lot of other languages are available by default. But this dialogue has been geared toward the MS Windows OS, but you probly figured that already.