The Tempest, by William Gates

If you spot a battered Ford Transit lurking in your office car park, supplied at regular intervals with cappuccino and Danish pastries, then be sure to switch off any PC running illicit software - the suspect vehicle may be a Microsoft licence detector van (LDV).

The boffins at MS's Cambridge labs have invented a way to monitor the radio signals given off by users' PCs to check whether they have the full compliment of software licences. These are known as Tempest signals, and PC Dealer can exclusively reveal that MS has devised the Billfort Scale to measure their strength, as follows:

0 - Calm. All licences fully paid up.

1 - Light air. All software is legitimate, but someone in accounts hasn't read their licence agreement.

2 - Light breeze. All licences paid for and read, but registration cards have not been returned.

3 - Gentle breeze. Some users are still calling the MS helpline after their three months' free support has expired.

4 - Moderate breeze. The chief accountant has copied Office 97 on to her notebook without buying an extra licence.

5 - Fresh breeze. The managing director has a bootleg CD of Money 98 which his son swapped in the school playground for two marbles and a Pamela Anderson screen-grab.

6 - Strong breeze. Whenever staff leave, they duplicate their PC software onto a Jaz disk. Umbrellas can only be used with difficulty (that's from the Beaufort Scale, but I couldn't resist it).

7 - Near gale. Apart from bundled packages, all the company's software is delivered at night in an unmarked van with Portuguese number plates.

Users are learning Portuguese in order to read the manuals.

8 - Gale. The company once bought a few copies of Word 2.1, but now has over 100 PCs running Office 97 and can't seem to remember where they came from. Users are confused because their Word 2.1 manuals don't mention Excel or Access.

9 - Severe gale. All the company's software was acquired at a car boot sale on a single CD-Rom for 49 quid. Users rely on tea leaves and Tarot cards to work out the applications.

10 - Storm. Users have burgled MS's duplication plant and stolen its entire contents.

11 - Strong storm. A distributor has burgled MS's duplication plant, stolen its entire contents, and sold it into the channel.

12 - Hurricane. Fully licensed copy of NT has just crashed for the147th time. Incensed users have realised they are under observation, descended en masse to the car park and overturned the LDV.

Unfortunately, MS has spoiled the fun by refusing to deploy its LDVs on the grounds that it would be too Big Brotherish (surely, ironic?).

So if you really do spot a battered Ford Transit, don't worry, it's probably just the courier.