Those who ordered the free CD containing Windows XP service pack 2 (SP2) three or four weeks ago should have now received it. If you're on a dialup connection and still haven't ordered it, do so by following the links at www.microsoft.com/australia/ and it should be in your mailbox in a week or two.

If you have any suspicion that your XP system could have adware, spyware or a virus, the first job is to clean out these nuisances before installing the service pack otherwise you might be compromising SP2's new security features.

Lavasoft, www.lavasoftusa.com, have their free Ad-Aware program to rid your computer of adware and spyware. After you've downloaded and installed the program, run it the next time you're online and get it to update its definition file from the Lavasoft site. Now let it do a complete scan of your system - it can take a while - and have it clean out all the nasties if finds. The Lavasoft website has a long list of adware and spyware produced by certain companies, but some common names are Gain, Gator, Dashbar, WebHancer and Cool Web Search.

A common means for adware and spyware to invade a computer is through file sharing services such as Kazaa and iMesh. If you suspect your computer has had one of these types of services installed at some stage it's important to download and install Spybot Search and Destroy to ensure you get rid of all variations of spyware. Spybot is also free and it works in a similar manner to Lavasoft's Ad-aware but deals with more vicious types of spyware.

In a lot of cases where your computer has been behaving strangely can be due to adware or spyware. However, if you suspect a virus, then it should have been already detected by your antivirus program. If for whatever reason your antivirus protection is not up to date and you don't want to pay for further updates, uninstall your current antivirus program and download and install one of the free ones such as AntiVir or AVG (see the links in this week's list of sites).

Before inserting the SP2 CD, log in as administrator and exit all programs including MSN Messenger and your antivirus program. To do this, go down to the system tray at the bottom right of your screen and hover the mouse over each icon. When you've found MSN Messenger, right-click and choose Exit. Each antivirus program is a little different but you want to turn off background scanning so it could be as simple as clicking on Exit on the popup menu after right-clicking. Don't worry about warning messages - everything gets turned back on after SP2 is installed.

To start the SP2 installation, insert the CD and click a couple of times to let it do its job. It takes about twenty minutes, depending on your system, and at the end you'll need to let it reboot.

Log in as administrator - it takes a bit longer the first time as XP sorts out a few things - and check out the new Security Centre which contains three elements: Windows Firewall, Automatic Updates and Virus Protection.

If you've been using another firewall besides XP's up to this point, you'll need to decide which to leave turned on as XP will advise you that two firewalls running on your system can cause instability. XP's new firewall has the advantage of being turned on as soon as you boot your computer, an important feature for broadband users. It's called a stateful firewall because it won't accept any data from the Net unless a program on your computer sends out a request, for example, you want to load a new page in Internet Explorer.

The Security Centre will also keep an eye on updates to your antivirus program, including free ones such as AntiVir and AVG. You'll be prompted by one of those balloon messages if you're getting behind in your updates.

Automatic Updates is now turned on all the time to save us from ourselves. It's a nuisance when your connection to the Internet is through a slow dialup connection but it's better to be safe than sorry. In fact, by the time you keep your system updated through a dialup connection these days, there's not much time left for any fun on the Net.

In the next column we'll look at how to make best use of the Information Bar and Popup Blocker in Internet Explorer. By then you will have experienced how much activity used to go on behind our backs when visiting some web sites.

For those who've installed the new Windows Media Player you might be wondering where the radio guide has gone to. Don't worry, it's still there!

When you're online, click on Guide and when that page loads, find the link to the International Guide - there's one at the bottom of the page. After this page loads, look on the right-hand side for Radio Tuner - click on this and you'll be on the familiar page from which to choose your radio station. Next time you want to choose a station, Media Player will remember to load the International Guide from which you can choose the Radio Tuner page.