The Windows 8 improved the Task Manager over the previous versions of windows. The some changes of the windows 8 task manager it is showing the total percent usage at the top of the your processes, which is decide to total memory and CPU usage, improved the Performance graph, App history tab instead of Application tab that gives you the total resources an app has used over a period of times, and in windows 8 add a new tab in the task manager Startup this tab to see startup processes and their efficacy to system performance, and now in windows 8 update the shortcut key to open task manager (ctrl+shift+Esc).