Essential free software for your PC

Want to see it spin on its axis? Choose Time > 10x Faster. Repeat this twice so that it's running at 1,000x normal speed and you'll see it majestically turning. You can use this trick to examine the orbits of other objects. Use the Navigation menu to move around space. Choose Select Sol > Go To Selection to zoom in on the sun.

Alternatively, click an object in view and then choose Navigate > Go To Selection. See the annotation to find out about some of the other useful navigation tools to help you find your way around

Protect your PC with ClamWin

Anti-virus protection needn't cost you £30 a year!

ClamWin isn't the only free anti-virus program for Windows, but its competitors are offered commercially as part of a strategy to generate more sales for their paid- for products that invariably contain more features.

ClamWin is open-source and therefore guaranteed to be free for its lifetime. It's a traditional anti- virus application and so you'll also need protection against spyware and a decent firewall, but it offers all the features generally associated with anti-virus programs.

You can set it to update regularly via the internet and run scheduled scans of any part of your system. It'll check outgoing and incoming email for viruses and you can set it to send an email alert if a virus is found, in case you're not at your PC at the time.

The main program window is straightforward to navigate. To scan a drive, select it and click Scan. Click the Internet Update button to obtain the latest virus definitions. To schedule operations, choose Tools > Preferences > Scheduled Scans. Click Add and provide the frequency, time and day for the scan and the drive or folder you want to test.

On the Internet updates tab you can configure the frequency of updates and the time for them to happen. Add an email address to the Email Alerts tab to be notified of virus detections.

Receive podcasts with Juice

The internet is flooded with all manner of interesting multimedia content – so much so in fact, that it can be difficult to keep up with it all. Juice is a media aggregator that enables you to select audio files or podcasts from thousands of available locations. You can then set it to record and save these shows at specific times.

While many podcasts are available for several days, some have a short lifespan and can be easy to miss. The beauty of Juice is that you can schedule recordings to ensure that you don't miss a thing.

It works using RSS (which stands for Really Simple Syndication) files to manage your subscriptions. You can use Juice's directory to browse through a large selection of providers or enter an RSS URL from any podcast's web page. Usually these are listed under links marked Subscribe.

Find one using your browser, right-click it and choose "Copy Link Location". Back in Juice, choose Tools > Add a feed and paste the URL here. Click Save and then move to the Subscriptions tab to see current available episodes on this feed. Juice isn't fully Vista compatible, but the Ogasa Walrus blog has some handy tips to get it working, which Vista users have found helpful.

Publish documents with Scribus

It's the DTP tool that puts Microsoft's Publisher to shame. Scribus will help you design a page or document for printing, once you have your text and images to hand. While you can enter text into a DTP program, it's better to use a word processor to write your information first, because this minimises the need to zoom in and out of the page to make it fit. Each page is made up of different frames, including text frames, image frames and tables. Start by setting up the format of the document.