Many of us know how to perform simple maintenance on our cars - changing oil, tyres, or windscreen wash fluid. But looking under the bonnet of Windows leaves the majority of people perplexed. In this feature we'll take a look at the engine room of Windows: the Control Panel.

You will learn how to tweak Windows to make it look and feel the way you want it to, diagnose faults, tell technical support engineers exactly what's wrong with the PC and even fix simple problems yourself.

The more you learn about the role of the Control Panel in Windows, the better you will understand how your computer works. Although we'll be working with the most recent version, Windows XP, you will find that much of the advice can be applied to the Control Panels in earlier versions of Windows, such as Windows 98 and Windows Me.

XP users may also find that some of the buttons are not quite the same in their particular version, or perhaps are not there at all depending on whether you've downloaded Windows Service Pack 2. Not to worry, though, all the important stuff here is relevant to everyone.

Taking a view
The first job is to choose how to look at the Control Panel. Click on the Start button and choose Control Panel from the list that appears. The Category View was introduced in XP to make it easier for people to access settings by theme, but it doesn't offer the kind of flexibility that is found in the other version, called the Classic View. In this feature, we're going to work in Classic View, so first make sure you have the correct view by using the following instructions.

To switch to Classic mode, open the Control Panel and click on the link in the left-hand panel marked Switch to Classic View. You will then see the Window change to contain a set of icons, each one relating to a different part of the system. The view will be familiar to anyone who has used the Control Panel in Windows 95 or 98. To open one of these Control Panel icons, simply double-click on it.

All systems go
The most important icon in the Control Panel is the one marked System. It controls the most in-depth options regarding the workings of your computer. Open it up and you will see a dialogue box with seven tabs, the first of which is marked General.

This shows the operating system you are using, as well as details such as whether you have Service Pack 1 or 2 installed. It will also show some information about the computer, such as what processor it has, how fast it is and how much memory the computer has. These facts can be useful if you are diagnosing a fault or talking to a technical support person.

The next tab, Computer Name, is handy if you have a home network. You can set the computer's name by clicking on the Change button. If someone else looks after the network, he or she will have set the name and you should not change it. If you do not have a network, this screen will still appear, but changing the settings won't have any effect.

The third tab, Hardware, enables you to examine and change settings for individual components of the computer, both internal and external. Clicking on the button marked Device Manager will display a window listing all the hardware inside and connected to your computer, including disk drives, monitors, network cards, modems, scanners and more, all arranged into categories.

To discover more about a category, click on the + sign next to it and it will expand to show all the relevant devices. Any device that has a yellow exclamation mark next to it is not working properly. You should note these down if you are going to talk to a support engineer or a helper on an online forum.

You can easily cause your computer to stop working by changing Device Manager settings, so it is worth being extra careful here unless you are following specific instructions.

Clicking on the Driver Signing button lets you choose whether to accept drivers for devices that haven't been given Microsoft's seal of approval. Since many legitimate third-party drivers haven't been passed, it's worth leaving this on the default 'Warn' setting.

The Windows Update button, if checked, enables your PC to automatically search the internet for device drivers when hardware problems arise.

The Advanced tab contains, as you might expect, some rather complicated settings, and that way danger lies. Unless you're an expert, don't adjust any setting that we haven't specifically mentioned. But there are still a couple of useful sections.

The first Settings button in the Performance section, brings up another dialogue box. Here you can choose the visual effects Windows uses, such as shadows and transparency settings. It's best to leave it set to 'Let Windows choose what's best for my computer' but you can change any of these display settings if you wish and then recheck the box to go back to the default settings.

The Advanced tab of this box contains settings for virtual memory. You should usually let Windows manage this itself as well, but if an engineer tells you to change the virtual memory settings, navigate to this tab and press the Change button.

Windows XP's System Restore can turn back time on your PC, deleting drivers or other settings changes that have not worked out as promised; it is best not to change anything here.

The next tab, Automatic Updates, controls how often Windows accesses Microsoft's XP repair website, and this is where the software patches that fix the infamous Windows flaws are found. You can set it to download and install everything automatically, or download updates and ask for permission to install them, or not download anything.

We recommend leaving it on the second option if you have broadband, so you know what Microsoft is adding to your computer. Dial-up users should choose the option to notify before downloading, as some updates can be quite large.

The final tab, Remote, allows engineers to remotely control your PC and fix problems but is not usually used for home computers. To prevent anyone getting unauthorised access to your PC, you should make sure the second box, marked 'Allow users to connect remotely to this computer', is not ticked.

Adding hardware
Windows XP is very good at detecting when you have plugged something in or installed a piece of hardware. It can often install the required drivers itself, or it will prompt you to insert the disk that came with the device. If, however, you install or plug in a piece of hardware for the first time, and it is not recognised by Windows, open up the Add Hardware control panel.

It is actually a wizard, which will take you through the step-by-step process of figuring out what you have plugged in. Click on Next once it opens, and it will search for the device, and prompt you to install the drivers if it finds the device.

If it can't find the device, it will ask whether or not the hardware is plugged in. If it is, it will then allow you to choose the device's name from a list. If the device in question is not in the list, scroll down to the bottom and select the entry marked 'Add a new hardware device', and click on Next. You can then once again ask Windows to search for it or select it yourself from a list.

Since Windows has already tried and failed to locate the device, it's probably best to find it yourself. Click on 'Install the hardware that I manually select from a list (Advanced)' and click on Next. It will give you a list of hardware types. Choose the most appropriate and click on Next, then try to find your device's manufacturer and model number from the list that appears. If you have a driver disk, press Have Disk and follow the prompts.

Add or Remove Programs
Normally, to install a piece of software, you simply insert the CD on which the program is supplied, and wait for the installation process to automatically begin. If it does not, you could try using the Add or Remove Programs control panel.

Open it up, and click on the button in the left-hand panel marked Add New Programs, then click on 'CD or Floppy' and follow the instructions. You can also use this screen to update Windows, by going to the Windows Update website.

The Add or Remove Programs control panel is more useful when it comes to removing programs from the computer. You may be able to do this by finding the program's folder in the Start menu and looking for an entry marked Uninstall or Remove.

Clicking on this will bring up a dialogue box that will take you through the process. Some programs don't offer this feature, so to remove such a program you will have to use this feature of the Control Panel.

On the first Add or Remove Programs screen, marked Change or Remove Programs, you will see a list of all the software that has been installed on your computer (except Windows itself, which we will come to later).

Windows XP also shows how much space the program is taking up on the hard disk and, if you click on an entry, how often it is used, and when it was last used. Clicking on an entry also displays either one or two buttons, marked Change/Remove or, separately, Change and Remove.

Clicking on either one will bring up a dialogue box explaining the process of either changing or removing entirely the application in question. Note that some core programs and updates to Windows, called Hotfixes, are listed, and removing them will make your computer less stable or unsafe.

In addition, some programs (and many games) will remove saved data and settings that have been created when they are uninstalled, such as favourite websites in a web browser, so make a backup of everything you might want to keep.

You can't remove Windows itself using this control panel, but you can make changes to the extras and utilities that come with it. Open up the Add or Remove Programs control panel and click on the third button in the left-hand pane, marked Add/Remove Windows Components.

This will display the Windows Component Wizard, which contains a list of extras and utilities to choose from. The ones that are ticked are already installed. Unticking these boxes will remove them, and ticking others will install those. Some have extra options; click on the Details button if it is active and you will see another box with more options.

Some of these programs, such as Internet Explorer and Networking Services, are core parts of Windows and should not be uninstalled, while others, such as Windows Media Player or Outlook Express, can be removed if you don't use them. Make the changes you require, click on Next and follow the prompts to make the changes you selected.

User accounts
User accounts manage the way that multiple users of a PC, such as family members, use it. Each user account is saved with information about how the user like to work, such as their chosen Desktop picture, documents folder, Desktop icons, favourite websites and password.

The Administrator account is the ruling authority for the PC. Even if you are the sole user of the PC you should set your own password, as this makes the computer more secure online. You can also add new accounts from here for other users.

Make sure they know that the Administrator account can be used to access their documents and list of visited websites, and set the security level for when they use Internet Explorer (we'll get to that soon). This is handy if you're a parent keeping tabs on the sites your children visit.

You will see that a Guest account is listed, which will usually be turned off. Turning this on means you can allow someone to use the computer, but they will not have access to any password-protected folders nor will they be able to change settings. It is usually best, for security reasons, to leave this account off.

Make a date
Using the Date and Time control, you can change the date or time from the first tab of this control panel, using the drop-down boxes and switches. In the second tab, you can change your time zone, so that programs can accurately calculate dates and times with respect to other users around the world.

Select your time zone from the drop-down box. For the UK and Ireland, the appropriate entry is marked '(GMT) Greenwich Mean Time: Dublin, Edinburgh, Lisbon, London'. Ticking the box at the bottom makes the computer correct the time when the clocks go forwards or backwards.

You can also, in the third tab, ask the computer to synchronise with an internet-based clock. In theory this is a good idea, but in practice it doesn't seem terribly accurate. If you want to experiment with it, tick the box, choose a server from the drop-down menu (it doesn't matter which one) and click on Update Now.