Microsoft's operating systems have been scriptable since pretty much the beginning of the PC revolution. MS-DOS and older versions of Windows use a simple batch scripting language, whereas modern Windows (and supported older versions) can make use of PowerShell, which enables extremely powerful scripting and automation in Windows.

I use PowerShell for a lot of stuff. It can load any .NET assembly, which makes it highly extensible, and of course, Microsoft's documentation is generally very good. PowerShell is great if you have a lot of raw text you need to process using regular expressions and the like - the .NET regex engine has some unique features you won't find on other platforms (including Perl).