Internet Explorer, Firefox, Opera and other browsers keep accurate records of your online activities, and not just in their history records. Clearing out the virtual breadcrumbs in your Internet cache and browser histories preserves your privacy and can improve your PC's performance by freeing up disk space, too.

Sites embed small text files containing information about you on your PC when you visit them. These are called cookies, and as a rule, aren't a threat to privacy. These files usually exchange information only with the sites that placed them, and any sensitive content is often encrypted.

Nevertheless, the mere presence of cookies with questionable names could cause problems. Anyone who has access to your system when you're away can see not only which sites you visit, but also the contents of unencrypted cookies.

All browsers save HTML (hypertext markup language) files and images from pages you visit, so they can load them much faster next time. Called caching this lets you view pages - minus some dynamic features - while offline. But the cache also serves as a record of your Web travels. Firefox and Opera keep track of your file downloads as well as your Web-browsing history (which IE also logs). Follow our step-by-step guide to wipe the slate clean.

1. To delete your browsing history in Internet Explorer 7 select Tools-Delete Browsing History-Delete all. You can also choose to only delete selected items (such as cookies, history, etc) by pressing the appropriate button.

2. If you want to limit the amount of browsing history Internet Explorer 7 keeps, click Tools-Internet options-Settings (in "Browsing history" section). In the "History" section, edit the number of days you want to keep a history of - the higher the number, the more browsing history is stored. Click OK when done.

3. In Firefox 2, a button labelled Clear Private Data erases all your browsing history, including history, cache and cookies (depending on what you select). This can be found under the Tools menu or by pressing <Ctrl>, <Shift>, <Del>.

4. If you want Firefox to delete your browsing history every time you close the application, click Tools-Options-Privacy. In the "Private Data" section, select Always clear my private data when I close Firefox. Untick Ask me before clearing private data if you don't want a prompt each time you close your browser. Click OK when finished.

5. To cover your tracks in Opera, click Tools-Delete private data. In the new window, click Details to display a list of everything Opera will delete, allowing you to customise exactly what you want to keep or remove. Click the Delete button.

6. To adjust the amount of browsing history and caching you want to keep in Opera, click Tools-Preferences-Advanced. Click on "History" in the left-hand menu and adjust settings from the drop-down menus. Click OK when done.

HELPFUL DOWNLOADS

THWART HIJACKERS Your browser is just that: yours. The last thing you want is for someone else to take it over. SpywareGuard watches several components of Internet Explorer to make sure no one hijacks your browser or tries to slip spyware into it. If an invader attempts to sneak in, it will let you know (www.javacoolsoftware.com/spywareguard.html).

BLAST SPYWARE Shut the door on spyware. SpywareBlaster sets a "kill bit" for spyware's ActiveX controls, but leaves harmless ActiveX controls alone. With the program installed, Internet Explorer won't download spyware, so you'll even be spared its "Are you sure you don't want to install this detrimental program?" nags ( www.javacoolsoftware.com/spywareblaster.html).

OFFICE SAFETY We're used to associating danger with Web sites and e-mails that might have viruses, but the truth is that the Word document you receive over your own computer network might contain risks all of its own. The Trace utility gives you a security risk rating exposing the presence of any hidden information in your Office documents (www.workshare.com/products/trace).

SPOT SUSPICIOUS BEHAVIOUR Everyone knows you need antivirus software to combat known threats, but what about those viruses that sneak under the radar before code is written to counteract them? AVG Anti-Virus spots programs that act like viruses, locks them up and puts them in isolation - even if no one's issued an all-points bulletin and corrective code (www.free.grisoft.com).