I am currently working on a SaveAs feature to some special file formats, those files are very very big. Before actually saving the file, I need to compute its anticipated size and compare it with the free disk space to see if there is enough storage for that operation. After searching a bit about how to get the free disk space, I came across the solution which uses the System.Management namespace. This namespace provides access to a rich set of management information about the system, devices, and applications instrumented to the WMI infrastructure. But, what the hell is WMI?

WMI is Windows Management Instrumentation and is part of the Windows operating system that provides management information and control. WMI provides extensive instrumentation to accomplish almost any management task and help us obtain information about our system. Applications and services can query for interesting management information such as how much free space is left on the disk, what is the current CPU utilization, which database a certain application is connected to, and much more, using classes from the System.Management namespace. Here is the MSDN page about the Windows Management Instrumentation.

Let me show you how to query the free disk space using WMI: