c# 'Invalid class' in a simple WMI query

user_675382 0
Viewed 15149

I will like to find some result after this query, but in the beginning of the foreach loop, the error "invalid class" occur.

string wmiQuery = string.Format("SELECT * FROM Win32_Process");
var searcher = new ManagementObjectSearcher(wmiQuery);
var wmiResults = searcher.Get();

foreach (ManagementObject retObject in wmiResults)
 {
   Console.WriteLine("[{0}]\tName: {1}", retObject["ProcessID"], retObject["Name"]);
 }

I use window 7 64, and i wonder if Win32_Process exists. I also use wmi code creator download it from http://www.microsoft.com/downloads/en/details.aspx?familyid=2cc30a64-ea15-4661-8da4-55bbc145c30e&displaylang=en but i dont find any Win32_Process.

Somebody has an idea ?

wmi-query wmi windows c#
4 Answers

In my opinion the exception does not sufficiently state the problem. The code below works. If you for example omit "\cimv2" in the scope the exception occurs. If you for example erroneously select from "Win32_Processes" the exception also occurs. Hence at least make sure the scope is correct and the query is correct.

ManagementScope scope = new ManagementScope(@"\\localhost\root\cimv2");
ObjectQuery query = new ObjectQuery("SELECT * FROM Win32_Process");
ManagementObjectSearcher searcher = new ManagementObjectSearcher(scope, query);
foreach (ManagementBaseObject eachObject in searcher.Get())
{
    Console.WriteLine("Value: {0}", eachObject);
}
user_33311850

Just to add as this is first thing that pops up on google search and having issue myself here C# wmi query exception invalid class using ManagmentObjectSearcher

Not all WMI providers have a 32 bit and 64 bit version. You may get invalid class if running a 32 bit application on 64 bit machine. I know that is not the case in this particular situation since Win32_Process has a 32 bit and 64 bit provider but figured it might be useful for some arriving here.

user_80664940
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