Microsoft acknowledged that its Windows 7 USB/DVD Download Tool does indeed include open source code. To correct the error, the company next week will make the source code and binaries for the tool available under terms of the GPL v2 licence.

Microsoft representative Peter Gali confirmed in a blog post that the tool does include GPLv2 code. He said the tool, offered through the Microsoft Store, was created by a third-party. But Gali did not shirk responsibility, saying Microsoft did not catch the error in its code review.

Earlier this week, Microsoft pulled the Download Tool after a prominent blogger accused the company of using open-source code without acknowledging where it originated. The tool helps users of netbooks that lack a DVD to install Windows 7.

The Download Tool is free and was made available to users to create bootable USB drives or DVD backup media from the electronic editions of Windows 7 that come in an ISO format.

Gali also wrote that Microsoft is "taking measures to apply what we have learned from this experience for future code reviews we perform."