Process explorer lets you replace the functionality of task manager with Process Explorer through a menu item that says "Replace Task Manager". Once you have done this the menu item should change to "Revert to Task Manager" or something like that. It used to do it, now it stays as Replace Task Manager even when Task Manager is already replaced. The only way to revert it is to go into the registry and remove the entry "Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\taskmgr.exe" and remove the debugger entry.
