Some WMI statements don't work (C# code)

[MrSeanKon]

For example the Win32_Fan, CIM_TemperatureSensor etc.........
gizmo you know the source code.
On the other hand CIM_Processor, Win32_Processes etc work....
Am I wrong?????????

[Gizmo]

I am very lost on this one. These calls should work, but for some reason they aren't. I've not been able to figure out why.

[Gizmo]

Oh DUH!

Win32_Fan, CIM_TemperatureSensor, and many other classes rely on the drivers to provide the necessary information. If the drivers do not provide the information via WMI, then you won't be able to read it.

To see if the particular class you are interested in is supported by your particular machine, you can run 'wbemtest' which provides a rudimentary interface for enumerating and interacting with the various WMI classes.

[MrSeanKon]

Thanks for reply gizmo.
Thus I don't see anything until Microsoft update its WMI??

[Gizmo]

Actually, it's not Microsoft's fault. It is the fault of your mobo chipset vendor.

In my case, it would be nVidia's nForce2 driver set which is the problem. nVidia would rather I used their garbage µGuru application than something that might actually work, so their chipset drivers don't properly provide information to WMI.

[MrSeanKon]

Thus we must work from beggining???

[Gizmo]

For some mobos and chipsets, yes.

[Áedán]

Originally Posted by gizmo

nVidia would rather I used their garbage µGuru application than something that might actually work, so their chipset drivers don't properly provide information to WMI.

I thought that µGuru was just an Abit thing? Where does WMI pull the data from? ACPI?

[Gizmo]

Sorry, you're right.

WMI pulls its information from a large number of sources. Much of the performance data comes from the performance registry. It also gets data via SNMP and the Event Log, as well as drivers that conform to the WDM driver model and support WMI directly.

Basically, WMI (which is Microsoft's implementation of the Web Based Enterprise Management standard, using the Common Information Model or CIM) is intended to pull together information from all of the previously disparate data collection systems in Windows, and provide them with a common interface, as well as providing additional data that was previously not available.

As WBEM was not part of NT4, MS provides a downloadable patch to provide the capability on NT4, and I believe there is a version for Windows98 as well. All OS versions from Windows2000 up have it already. WBEM is also implemented on Linux, Solaris, and BSD, off the top of my head (there are probably others).