Craig Mundie, chief technical officer at Microsoft, said the programme was designed to provide governments with information they need to conduct security reviews of Microsoft products.
IT staff within central government would be invited to visit Microsoft development centres in Redmond to examine Windows development, testing and deployment processes, and to discuss projects with Microsoft security experts.
Last year, company chairman Bill Gates said the Windows source code represented Microsoft's key intellectual property. During the long-running anti-trust trial the company fiercely resisted demands to hand over source code to competitors.
The news comes on the first anniversary of Microsoft's Trustworthy Computing initiative. Microsoft plans to take Trustworthy Computing beyond its internal focus in the next 12 months and bring security to the larger developer community.
Microsoft launched the scheme last year to make security inherent in every product it develops.
Microsoft chief security officer Stuart Okin said almost every development team in the company has attended training courses on writing more secure code and handling security breaches in the past year.
"We are trying to bring a consistent approach to handling security across different products," he said. "The Windows and Office teams are working on a common way to patch software."
Okin added that Microsoft would work to ensure sample code on its developer support, Microsoft Developer Network, reflected best practices in security. "We will put our official curriculum into the public domain."