WMI rocks, but it's common to be afraid of it. Yosi points to a very cool tool that will help overcome this fear and make working with WMI a little easier: Microsoft (R) Management Strongly Typed Class Generator - MgmtClassGen.exe
Example :
MgmtclassGen Win32_Logicaldisk /L VB /N root\cimv2 /P c:\temp\logicaldisk.vb
You can find it under you sdk bin directory, so instead of figuring out the properties of the objects you get a strongly type object to work with.