Some of the major resources in the operating system are the physical disk, memory, process, CPU and network. Any of these resources when not utilized properly, will be leading to performance deterioration resulting in process hang or high CPU consumption. Perfmon is a tool to visually display the built-in performance of the operating system by using the counters. Performance related issue is a common scenario for websites hosted in IIS and in this series of videos, we will be exploring how Perfmon can help us in troubleshooting some of them. We will also explore how Perfmon along with Windows debugger, can help us to troubleshoot High CPU related issues, by figuring out the thread ID of the high resource consuming threads and looking into the stack of that. These videos will help anyone who does troubleshooting be it a developer, system admin who wants to troubleshoot issues with websites hosted in IIS.