Using the Task Manager to diagnose problems
The task manager shows you all the applications and processes that are running on your computer, it can be a great tool to help diagnose and fix problems if your computer starts to run very slowly.
To open the task manager hold down the Ctrl key, hold down the Alt key and while they are both held down press the Delete key.
The task manager window will appear. This window has five tabs (Applications, Processes, Performance, Networking and Users). For the purposes of this document I will only discuss the first two of these tabs.
Application Tab
This is the default view that will be visible when you open the task manager and displays a list of all currently running applications (programs).
(If you need to switch to this view just click on the 'Applications' tab at the top of the window.)
If your computer appears to freeze, or an application stops working, open the task manager and view the application's status. In the picture above everything is working OK and all the running applications have a status of Running.
If one of my running applications had stopped responding it would have a status of Not Responding - in this case you can force it to close by selecting the unresponsive application and clicking on the End Task button. This will force the program to end (you will be prompted to confirm that you want to do this).
Be careful with doing this because the application may be busy or waiting for your input - you should only end it this way if there is no other option.
Before you do end an application it is worth checking that it is not asking you to enter some information - make sure that there isn't a dialog hidden behind another open window. Also, you should give the application a few minutes before you end it so that if it is just busy it has a chance to finish what it is doing.
IF YOU END AN APPLICATION THIS WAY YOU WILL LOSE ANY UNSAVED INFORMATION. PLEASE MAKE SURE THAT YOU ARE REGULARLY SAVING THE INFORMATION YOU ARE WORKING ON TO AVOID POTENTIAL LOSSES.
Processes Tab
The processes view shows all currently running processes on your computer. You can switch to this view by clicking the processes tab at the top of the task manager window.
So what is a process?
Essentially a process is a task that is running on your computer. An application is actually made up of one or more processes. In addition, there are many running processes that are part of the operating system, for example there will be a process for sending information to a printer when you print a document.
Also, there are many processes running that are not part of the operating system and don't appear to be part of any of the running applications. For example, if you have anti-virus software on your computer there will be a process running which monitors all files opened on your computer to scan them for infection.
Don't worry about the processes that are running - the names don't really mean much (you may be able to guess what some are, for example in the picture above you will see one call WINWORD.EXE - this is the main Windows Word application process).
This tab can be very useful if your computer appears to be running very slowly. You will notice in the picture above that the last process (System Idle Process) has a CPU value of 95 - this denotes that the task is taking up 95% of the computer activity.
The System Idle Process is basically the spare capacity of the computer. While it will fluctuate as other processes do things, you should see that it is in the region of 80-90% at any time (it may briefly fluctuate to a lower level if your computer is busy but should return to a high value very quickly).
You will see a value at the bottom of the task manager called 'CPU Usage' - you want this value to stay fairly low (averaging less than 10%). This is the opposite number to the system idle process value. When the system idle process has a CPU value of 95% the CPU Usage value will be 5%.
There are some applications that perform continuous calculations using the spare capacity of your computer, a good example is the BBC Climate Experiment which can be downloaded and installed to perform climate modeling calculations. If your computer has software like this running you will find that your CPU usage is constantly at 100% as this software uses all spare capacity. The advice in this section of the document is not valid to you.
If your computer is running particularly slowly open the Task Manager and look at the running processes. Is the Idle process showing a low value? If so, can you identify another process that is taking this capacity from the Idle process? If there is you can attempt to end the offending process by clicking End Process.
Before you end a process this way you should first try to shutdown the computer in the standard way. Shutting down the computer is a much cleaner and safer way of resolving this sort of problem. Ending individual processes can leave your computer unstable resulting in unpredictable results.