Common Windows Scripting Languages
Everyone knows that PowerShell is the new hotness for scripting on Windows. Microsoft is promoting it heavily, and many of their GUI-based administrator tools even use PowerShell. This is all well and good, but most Windows systems administrators will have to deal will legacy scripts as well.
PowerShell has actually been around for a few years, but it has really matured in the last couple years and is now a very viable option for most needs. One possible downside is compatibility on older operating systems such as Windows XP and 2003. PowerShell is not installed by default on these operating systems, so you need to install it somehow (e.g. SCCM or WSUS), and unfortunately the highest version that can be installed is 2.0. To get started with PowerShell you can read TechNet or read a book such as the highly-reviewed Learn Windows PowerShell 3 in a Month of Lunches.
Before PowerShell the scripting language of choice for many organizations was VBScript. All currently supported Microsoft operating systems, and even older ones like Windows 2000, support VBScript out of the box. Many organizations have used it (or continue to use it) for a decade or longer, so don’t be surprised to see it if you are hired as a Windows systems administrator. Resources to learn VBScript are available on MSDN, and many excellent books are available such as Microsoft VBScript Step by Step. If you are already familiar with VBScript and want to learn or work on migrating to PowerShell, Microsoft has you covered. They have a series of articles available on TechNet that will help: The VBScript-to-Windows PowerShell Conversion Guide
A lesser known scripting language that is still in use is KiXtart. This language is particularly easy to get started with, especially for creating logon scripts. The official documentation is good and many examples can be found on the official site and forums. It is not supported by Microsoft so you must make the executable available to systems that need it. Note that it doesn’t seem to be officially supported on Windows 8 or 2012. If you are new to scripting you would be better off learning PowerShell or VBScript, but basic familiarity with KiXtart can be helpful if you are being interviewed or are hired by an organization that still uses it.
This article would not be complete without at least a mention of batch files. These are still widely used, and they are suitable for many simple tasks. It is a good idea to have some basic familiarity with batch files. While a more advanced scripting language will be the primary choice at most organizations, you still might find batch files in limited use.