Though I mentioned few Task Manager Replacement tools earlier but this one deserves a separate post and that is all because of its functionality.
No doubt Windows default task manager is a great way to list and kill processes but it still lacks certain features that are provided by this Task Manager called Extended Task Manager. Moreover you can make it to run either directly by double clicking or configure it so that it starts in place of the default Task Manager when Ctrl + Alt + Del are pressed.

Features:
• Apart from all the general features provided by default Task Manager, this provides details of files currently locked by some other processes.
• If you need to know more about some process then just do a Google search right from the tool.
• More detailed process information.
• Small and light to use.
Download Extended Task Manager

If you are bored up with the default Windows Task Manager and its simple functionalities then you can try a new and improved Task Manager called Security Task Manager.

Security Task Manager provides the users with lots of information apart from the usual process information. Security Task Manager shows comprehensible information about programs and processes running on the computer. For each Windows process, it improves on Windows Task Manager, providing:

• unique security risk rating

• comments from the experts on the processes

• free online scan with all known Antivirus engines

• full directory path and file name

• process description

• CPU usage graph

• embedded hidden functions

• process type

The Security Task Manager detects unknown malware and rootkits hidden from the antivirus software. Furthermore you can put a process into quarantine or search the internet for information about that process.
Download Security Task Manager

Windows task manager is quite simple and don’t have much of the features so if you are looking for some task manager that can give you enough information of the processes running in the background then you should try this process explorer called System Explorer.

Though I have mentioned about the replacement task managers but this is bit detailed and also simple to use. Features of System Explorer are:
• Detailed informations about Tasks, Processes, Modules, Startups, IE Addons, Uninstallers, Windows, Services, Drivers, Connections and Opened Files.
• Easy check of suspicious files via VirusTotal or Jotti service.
• Easy search details about file/process via online databases.
• Launcher (”New Task…” dialog) with integrated AutoSearch and AutoCompletion.
• Action History for monitoring processes activities.
• Performance graphs for monitoring usage of system resources in time.
• System Snapshots for easy finding of system changes.
• System Report builds rich text report containing major informations about your System.
• Multilanguage and Plugins Support.
• Version 2.0 brings brand new user interface and Windows 7 support.
• Security feature with online File Reviews.
• WMI Browser and System Additional Info
System Explorer is a freeware and fairly simple to install and use.
Download System Explorer