What a bunch of clever clogs they are down at the Department of Health.NHSnet fell over, companies worldwide had to close down their computer systems, and even the US National Security Agency suffered a security breach.But apparently the DoH had no problems at all with the 'love bug'.

Two explanations spring to mind: either Richmond House has highly advanced IT security - or even an e-mail worm didn't think it had a chance of convincing civil servants someone loved them.

If, unlike the DoH, you are still suffering from unrequited 'I love you'messages, go to the F-Secure Corporation, ZD-Net, Carnegie Mellon University's CERT co-ordination center or any one of a dozen or so sites listed by Yahoo! for help.

With luck, love bug exper ience will make people wary of e-mail attachments in future.

But every office has someone daft enough to unleash mayhem on their colleagues.Our system had been back all of 30 minutes before the first suspect attachment arrived in my inbox . It turned out to be a particularly dull memo.

But it could have contained any number of horrors: the Good Times virus, which erases your hard disk; Irina, which over-writes it;

NaughtyRobot, which 'crawls into your server through a tiny hole in the world wide web' and captures all your personal data; or Death Ray, which blows up your PC.

So prevalent have these rogue programmes become that there are plans to 'turn off ' the Internet for 24 hours and clean out all the electronic flotsam and jetsum.So don't forget to disconnect all your terminals, local area networks and servers or you'll lose all your data.Actually, you won't. Internet Clean-up Day and all the viruses named here, except the love bug, are figments of the imagination.The US Energy Department has a list of hoaxes at its Computer Incident Advisory Capability site.The problem is that hoaxes are almost as time-consumingly damaging as the real thing.

These and other sites of interest can be reached via HSJ's website at www.hsj.co.uk