The NHS is a casualty of the drive to go digital

SIR – Government organisations such as the NHS have been pushed into keeping computer records, without any paper alternative or back-up, for the best part of a decade.

Whitehall policy has left us all vulnerable to cyber-attacks of the kind seen in recent days. Do not blame the hospitals and the doctors. Top civil servants have had a ridiculous faith in modern technology. This was all entirely foreseeable, and there were many warnings.

A major change in policy is needed. Nigel F Boddy

Darlington, Co Durham

SIR – Technical support for Windows XP stopped in April 2014.

NHS trusts in England have devolved powers. The health authorities that decided not to upgrade their computer systems have only themselves to blame, and heads must roll. Don Edwards

Lawford, Essex

SIR – The cyber-attack on the NHS and other organisations was against Microsoft Windows computers.

When IBM designed the original PC, the operating system selected was designed for computers that had no hardware security features. Since then, despite IBM’S Operating System/2 that was designed to be secure, Microsoft has been able to maintain its PC monopoly. The fundamental security flaw in Windows still exists.

Bell Labs developed the Unix operating system at the same time the PC was being introduced. Unix was designed to be highly secure. Apple’s OS, Google’s Android and the Free Software community’s Linux are all based on the Unix design, and as such are highly resistant to infection by malware. E H Bleasdale

London SW20

SIR – Tony Seba, a Stanford University economist, predicts that electric cars, or “computers on wheels”, will replace petrol and diesel vehicles within 10 years (Business, May 15).

That forecast sits very nicely with the computer-hacking headlines. Bill Parish

Bromley, Kent