NHS England has warned that “urgent action” is required from NHS organisations and GP practices which have still not migrated their computer operating systems away from the soon-to-be ditched Microsoft Windows XP platform.

Microsoft announced last month that it has ended support for the XP operating system, launched in 2001. This has left hundreds of thousands of machines across the health service needing to change software.

The national agency has told all relevant organisations that they must have a ‘premier support agreement’ in place before Tuesday 13 May. This will allow them to download software updates to fix system vulnerabilities.

All NHS computers can continue accessing technical support for Windows XP SP3, the software suite Office 2003 SP3 and the server software Exchange SP2 until 14 April 2015, thanks to a £5.5m deal between the software giant and the Cabinet Office.

The Department of Health, which is co-ordinating the migration effort, told HSJ said that the Health and Social Care Information Centre was still working to find out how many NHS machines continue to use Windows XP.

A DH spokeswoman said: “Our agreement with Microsoft enables NHS organisations to obtain critical and important security updates for Windows XP for a further 12 months beyond 8 April 2014, when support expires, and will save the NHS money.

“This deal will provide continuity for NHS organisations while they migrate on to alternative operating systems and we are working with NHS England and the [Health & Social Care Information Centre] to make sure they do so.”

Seperately, the DH, the Cabinet Office, NHS England and the HSCIC signed an agreement earlier this month to continue funding the NHS’s high speed internet service from April until 2017.

The contract for the N3 service, which provides broadband services across the NHS, is managed by BT, with some services provided by a range of suppliers on rolling contracts, with some central funding support.