Last week I had a call from two terrified foreign students. They sounded panicked on the phone and told me that they had been allowed to use the landlord's PC while he was on holiday.

All of a sudden it had stopped working. The clock was ticking until the landlord's return...I grabbed my kit for healing PCs and rushed to their aid. On arriving, I could tell at a glance that their computer was crawling with viruses.

A common way for viruses to enter a computer is from dodgy websites displaying photographs of the human anatomy. Although in this case, they probably found a great many other ways of picking up infections. Before I continue, I must state my geek-o-cratic oath prevents me from disclosing the detailed origins of this particular infestation.

Viruses are a curse of modern time. If you haven't had one, either you're extremely lucky or you've never owned a PC. They are a threat to your computer, your personal data and your sanity. They sneak in into your system and gather information gathering your private email contacts and using them to send spam to your friends. They might even try to get hold of your bank details or your login for an on-line payment system like PayPal. All of which could result in you losing your friends and your money, and mumbling to yourself all day on St James's St.

The students had one of the worst cases I've ever seen in my long career as a computer doctor. You could not even move the mouse without pop-ups littering the screen and bringing the system to a grinding halt.

I performed a quick system check from my magic CD. The results told me that there were evil root kits lurking deep down in the guts of the machine. Root kits are viruses that disguise themselves at a system level so even the virus checkers can't spot them.

After two hours of precision surgery and a lot of mopped brows, but without the need for a full lobotomy, the system was clean again. Final diagnosis: the PC had 366 viruses, 26 browser pop-ups, four worms and thankfully only one root kit. The patient made a full recovery and the students got to keep their deposit.

When it comes to computer viruses, prevention is better than cure. I'm always happy to help repair the problems causes by viruses, but there are things that you can do to protect yourself.

• don't open unexpected email attachments

• don't download anything from dodgy websites

• do a regular virus check.

You don't have to spend a lot of money on a virus checker. Many anti-virus software companies provide free on-line scanning of your system.

OnlineScanner :
Check out the following websites and visit them regularly.
Links for non trained PC-healing Personnel
[1] Symantec http://security.symantec.com/sscv6/default.asp?langid=ie&venid=sym
[2] panda http://www.pandasoftware.com/products/ActiveScan.htm
[3] bitdefender http://www.bitdefender.com/scan8/ie.html
[4] kaspersky http://www.kaspersky.com/virusscanner

Links for geeks and trained PC-healing Personnel
[1] Nessus http://www.nessus.org/
[2] Checkrootkit http://www.chkrootkit.org/
[3] Tripwire OpenSource http://www.tripwire.org/
[4] ClamAV http://www.clamav.net/
[5] John the Ripper http://www.openwall.com/john/
[6] Tiger http://savannah.nongnu.org/projects/tiger/
[7] Audit My PC http://www.auditmypc.com/free-spyware-removal.asp

If you do have problems with making your system virus free, give Conny a call.