If you’re experiencing a dramatic slowdown on your Mac or PC, you may be able to track down the culprit by using a process monitor. This will show you all of the programs and processes currently running on the computer, and how much of your system resources those processes are taking up. If you close out of all programs and still see a process taking up nearly 100% of the system resources, you’ll know what’s causing the issue. Then you can Google the name of that process and find out how to get it under control.
There are process monitors available on both Mac and PC. On the Mac, Apple actually includes an application that does this in the operating system. It’s hidden away in the Utilities folder, and is called “Activity Monitor.” This will break down all of the processes running on the Mac by how much of the processor, memory, energy, hard disk space, or network those processes are using. Just click on the tab at the top to view each category. To diagnose a problem, you’ll mostly want to focus on “CPU” and “Memory.”
Microsoft also has a program that will monitor your Windows PC, called “sysinternals.” You can download it for free at technet.microsoft.com. This is a suite of utilities that contains many tools for troubleshooting issues. If you don’t want the full suite, you can also get just the Process Monitor here.
source – TechGuyLabs.com