More problems with NatWest cash machines, many of which have now been "upgraded" to run Windows NT. News of two more malfunctions reached Mole last week. If greeted with the message "C:/Program Files/NCR/NCR.exe", do not attempt to withdraw cash as whoever used the machine last has probably lost his card. A possible, though drastic, solution would be for Natwest to fit Ctrl, Alt and Delete keys, allowing customers simply to reboot the errant machines. Alternatively you may prefer the strategy adopted by Mole's programmer pals as part of their year 2000 preparations and resort to the Quality Street tin under the bed.

In the overall scheme of things, the inability to withdraw cash may be the least of our worries.

According to a newspaper which reports on US governmental matters, the Aegis missile carrier, USS Yorktown had to be towed into port recently after it was left crippled with computer failures which put its propulsion system out of action. The computers were running Windows NT.

The Navy has been understandably keen to play the problem down and there are a few discrepancies between the official account of the incident and the account offered by Anthony DiGiorgio, a civilian engineer with the Atlantic Fleet. For instance, the Navy claims the Yorktown was out of action for only two hours. DiGiorgio says two days. The Navy also insists the boat never had to be towed. DiGiorgio remembers things differently.

A Navy source breezily pointed out that this is only the second time the Yorktown has suffered a potentially catastrophic system failure. A leaked memo about the first crash, which happened last year, traced the problem to "bad data", which caused the computer to attempt an abortive divide by zero operation. The result was a database overflow which brought down everything on the network.

Navy engineers see this as minor glitch in the application code. DiGiorgio disagrees. It's an operating system problem, he says.

"Your $2.95 calculator, for example, gives you a zero when you try to divide a number by zero, and does not stop executing the next set of instructions.

It seems that the computers on the Yorktown were not designed to tolerate such a simple failure."

The Yorktown is only one of a number of US warships undergoing "modernisation" - a euphemism, apparently, for a quick refit with cheap computers - and NT figures large in the programme.

Mole has never been to a Microsoft product demonstration at which the operating system of the moment did not crash, so there is a certain inevitability about the Yorktown's problems. So regular are these crashes that Microsoft officials have even taken to joking about them. At a recent demonstration of Windows CE to devotees of the ARM RISC core, the Microsoft presenter quipped that he had built in a spoof crash to his demo routine so as not to disappoint his audience. In the event, the machine stubbornly refused to boot at all, so we may never know what one of Microsoft's spoof crashes looks like.

The clearly partisan Mr DiGiorgio argues that the computer blunders that afflicted the Yorktown would never have been made by a proper operating system, Unix for instance. His complaints are falling on deaf ears. Understandably, US Navy officials have an innate respect for a company as dedicated as they are to world domination.

You might think Mole is scare-mongering, but he is not the only one worried about the potential for a computer activated catastrophe. US military chiefs are seeking multilateral agreements with other states, including the old enemy Russia, to guard against the possibility of war breaking out by accident as the clock passes midnight on 31 December 1999. The fear is that, in their disorientation, muddle headed computers will set off the world's early-warning systems. Forget planes falling out of the sky at the dawn of the millennium, it might be raining missiles.

On a more cheery note, if the year 2000 is to be our last laugh we might as well have a few more laughs at its expense. Among the less well-known by-products of millennium chaos Mole has discovered an insidious "paragraph cloning" virus, a severe outbreak of which has taken place at the Sunday Times.

In the Business section, a journalist by the name of David Parsley has re-used the following description of the causes of the Y2K crisis several times since the beginning of the year. "The millennium-bug problem has arisen because many computer systems use only two digits, not four, for their internal calendar. When the year changes from 99 to 00, many applications may crash and create indecipherable data."

Now the virus has spread from "Indecipherable" Parsley to his colleague Robert Winnett in the Money section. In an article entitled "Insurers turn their back on 2000 bug" Mr Winnett takes the Parsley standard paragraph and improves on it with the addition of two well-chosen words: "The bug occurs because computers only use two digits, not four, for their internal calendar. When the year changes from 99 to 00, experts say many applications will crash and create indecipherable data, causing chaos."

Perhaps the death and destruction scenario is wrong after all. The world will end not with a bang, but with a Winnett.

Advice on how to survive the millennium and other catastrophes is available free of charge from Underground Bunkers and Tinned Foods 2000 Ltd, a subsidiary of Molesoft Corp. The captains of becalmed warships should call Microsoft and ask for Windows NT Technical Support. Enjoy the hold music.