This error could occur due to cross-thread operations. You may want to check InvokeRequired and call your methods using either Invoke or BeginInvoke.

Hello, Have you tried this: ManagementObject processor = new ManagementObject("Win32\_PerfFormattedData\_PerfOS\_Processor.Name='\_Total'"); processor.Get(); ulong value = (ulong)processor.Properties\["PercentProcessorTime"\].Value; Valery.

You could have a look at the Thread class, paying attention to "processor affinity". I have strong doubts it makes much sense on any Windows system though, in my experience it isn't worth anything, i.e. the Windows scheduler does a good job distributing the load over the cores, and not switching threads around unduly. The one situation I would use it is when I had N groups of threads where each group needs to share a limited amount of cached data, so having all its threads on the same core really is relevant. When I have a number of similar/identical jobs, I tend to create up to 2*N threads where N equals Environment.ProcessorCount; then I let Windows make the best of it, which it does. And I don't use the ThreadPool in such situations. :) Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.