Recently my computer has become very slow after it operates for more than one hour, most frustratingly the words on the screen do not keep up with my typing and clicking on internet items does not always produce results. I have contacted my ISP several times and they have checked everything from their end and say that nothing is wrong. The NOD32 antivirus product is installed on the computer and there are no viruses. The computer is running Windows XP.

Your ISP is correct that the problem is most likely with your computer rather than the internet connection, simply because the entire computer is slow to operate (demonstrated by the computer not keeping-up with the speed of your typing) in contrast with the situation where the internet is the only thing running slowly (which could instead indicate a problem with the internet connection). So, we need to focus our investigation of the problem on your computer. As you may have read in previous columns, a fact of life when using computers is that over time there is a build up of many programs and redundant data on the computer. This is the result of installing many different programs over the lifetime of the computer, many of which are not uninstalled even if you don’t use the programs, and those which are uninstalled generally do not remove all of their data but instead leave quite a bit behind. Such extra data accumulates across the computer and in various Windows system locations such as the Windows Registry, which is essentially the system database for Windows that stores settings for various Windows services together with programs. The net result is that more data being stored on the computer, particularly in locations such as the Windows Registry which also stores other critical data, makes those locations much bigger and slower to access due to the amount of redundant or unnecessary data. When you potentially consider the amount of accumulated data after several years of computer usage this takes a significant toll on system performance.

Other than data, there is the effect of programs installed on your computer. In many cases, the installation of programs is somewhat of a one-way process. You install a program on your computer but, even if you don’t use that program, it is never uninstalled. While many people think that this doesn’t cause a problem, since if you don’t use a program then it will just remain installed on the computer but not accessed (taking up hard drive space but not much else, since the program is not running), this is not strictly the case. Many programs have “helper applications” which are also installed at the same time as the program, and are designed to provide support to the main program in various ways. For example, making it quicker to launch the program by pre-loading parts of the program in the background (hidden), or perhaps providing an auto-updating facility which allows for notifications to be displayed that updates are available, even if the program is not running. These helper applications are always running in the background on the computer, and even if you don’t use the main program it is possible that the helper applications will just continue running and consuming system resources.

From your description of the program, because the computer gradually slows down while it is being used, it is possible that the extra load of the programs that you launch (in addition to those which are running in the background automatically) are causing the computer to become overloaded and slow down. Alternatively, it is also possible that one of the programs which is running on your computer has been poorly coded and contains an issue such as a memory leak (essentially a problem whereby a program consumes more and more memory but never releases that back to the operating system, eventually resulting in an inordinate amount of memory being used by that program, significantly degrading the performance of the system). So, as part of our procedure to troubleshoot the issues being experienced we will need to remove unnecessary programs from the computer and then work towards determining whether a particular program or process running on the computer is responsible for the slow performance.

As a starting point, we should uninstall any programs which you do not use. This should also remove any helper applications (which automatically run in the background) associated with those programs, potentially freeing-up some more system resources as a result. Go to the “Start” menu > “Control Panel” and open the “Add or Remove Programs” control panel. Look through the list of programs for any which you don’t use and proceed to uninstall the programs. Be aware, there are often items listed in the Add or Remove Programs window which are add-ons or related to the system (such as driver packages) that you may not recognise. You should only uninstall items which you recognise and can positively confirm that you don’t use – if you encounter an item and are unsure about its purpose (or the implications if you uninstall the item) then you should err on the side of caution and not uninstall the item. However, you could always do some research on the internet to shed some more light on the particular item and, if at that point it is deemed not necessary, proceed to uninstall the item.

Once you have uninstalled any items which you know are not used, restart the computer so that any remaining steps of the uninstall process (such as the removal of files which are in-use) can be completed. We will now look at checking whether any potential programs or processes running on the computer are causing the slow behaviour. Before going any further, it is worthwhile providing a definition of a program and process, since these terms are often used interchangeably. A program generally refers to an application on the computer which you run and then interact with, such as iTunes. In contrast, a process is something which usually runs invisibly in the background providing support to a program. An example is the iTunesHelper process which is installed with iTunes and runs in the background, providing various support services for iTunes such as allowing iTunes to launch quickly by pre-caching files which are needed by iTunes. As you can see, because such processes run invisibly it is difficult to tell how many are running on your computer at any point in time. One way that you can tell what is running on the computer is by pressing CTRL + ALT + DEL to open the Windows Task Manager and click the “Processes” tab. This will show all processes currently running on the computer. Be aware, you are likely to see quite a long list of processes appear, since this lists all processes running on the computer – including system processes. You can tell which processes are not system-based processes (and have instead been launched under your user) by looking at the value in the “User Name” column. If this column is not visible, go to the “View” menu > “Select Columns” and tick “User Name”.

Next time the computer is running slowly press CTRL + ALT + DEL to open the Task Manager and click the “Performance” tab to show a break-down of the system load. In particular, we are interested in the CPU Usage and “Available” Physical Memory. If you find that the CPU usage is high, and/or the available memory is low, then we have an issue with system resourcing, most likely being caused by too many things running in the background (or a renegade program or process consuming too many system resources). We should be able to track down the process(es) causing the issue by going to the “Processes” tab and then sorting the table by CPU and Memory. When sorted by CPU you can ignore the “System Idle Process” as that will (generally) always have a high CPU usage since when the system is idle that is assigned the spare CPU capacity. We are more interested in other processes which are exhibiting a high CPU or memory usage. If you find a process is using a large number of system resources, and the process is running under your user name, try to determine from the name of the process (i.e. the Image Name column) what is the purpose of that process, or what is the program associated with the process (e.g. the firefox.exe process is obviously associated with the Mozilla Firefox application, but unfortunately not all are that obvious). If you have difficulty making this determination then you may wish to write down the name of the process and do an internet search when your computer returns to a working state. Once you have determined the program associated with that process try closing down the program to see whether that clears the system bottleneck. Should you find that the problem stops then it seems that particular program/process is causing the problem, so you may wish to continue further investigations in that regard (particularly whether an updated version of the software is available which does not suffer from this problem).

However, should you find that it is not just one single process that is causing the problem, but the cumulative effect of many programs and processes running on the computer, it may be time to do a clean-house on the computer. As you may have read in my previous columns, I generally recommend that after 1 – 2 years of computer usage you backup all data on the machine and do a complete format and reinstallation of Windows from scratch. This is designed to remove all of that accumulated data from the machine and bring it back to a factory state. On a similar topic, some people recommend the use of “registry cleaning” utilities and such which claim to be able to remove a lot of this unnecessary data from your computer. I advise against the usage of such utilities because, from experience, have found that they can cause more damage than they intend to fix (by inadvertently removing things from the computer which are actually needed).

Of course, if your computer is a few years old then you may also wish to consider upgrading, since it may simply be unable to run newer software which is more demanding on system resources. That said, it could be more cost effective to purchase a brand new computer from a big name vendor such as Dell, since they usually have fairly competitive pricing on new machines (plus you have the benefits of warranty and quality control as the machine was specifically built to handle the preinstalled software, such as Windows 7).