Microsoft and The National Archives are working together to overcome the problems of accessing the nation's digital heritage presented by outdated file formats.

The partnership will also improve the accessibility of documents by converting this information to new, open file formats which don't need Microsoft or other proprietary software to read and edit.

Organisations such as The National Archives, which hold many of the nation's 900 years of historical records, or the British Library, with its wealth of books, are currently busy digitising their collections.

But while on one hand digitisation helps preserve these records as paper and other medium such as microfilm become vulnerable with age, the rapid evolution of technology also puts them under threat.

Preserving digital formats can paradoxically be more challenging than the physical preservation of the papers that the records where originally created on.

The National Archives IT system, combines older versions of Windows and Office. Like many consumers, it can find accessing and managing these older file formats problematical.

Many older file formats or operating systems are no longer commercially available and upgrades to newer or different versions are not always backwards compatible.

Natalie Ceeney, chief executive of The National Archives, said: "Unless we take action, we face the certainty of losing years of critical knowledge. That's why it is essential that The National Archives, together with the IT industry, address the challenge now."

Microsoft will provide The National Archives with access to previous versions of Microsoft's Windows operating systems and Office applications using Microsoft Virtual PC 2007.

Virtual PC 2007, which can be downloaded free from Microsoft, enables people to run multiple operating systems at the same time on the same computer, allowing access to practically any document based on legacy Microsoft file formats. However, users have to have Windows XP Professional and upwards to make use of this application.

It is estimated that The National Archives will have to manage the equivalent of 580,000 encyclopedias in these formats.

Input from The National Archives will also prove useful to Microsoft and, in the long run, to other organisations and consumers as it is at the heart of setting standards for information and records management across the UK.