The issue focused on concerns about Microsoft's Windows XP software. IBM engineers began discussions with Microsoft engineers in January 2003 to express IBM's desire to sell computers running Windows XP and Internet Explorer 6. Microsoft engineers responded by describing Microsoft's hardware requirements for PCs that would support Internet Explorer 6. IBM engineers presented Microsoft with their PC specifications, which Microsoft engineers discussed with IBM engineers. IBM engineers agreed that Microsoft engineers could install Internet Explorer 6 on IBM PCs if IBM engineers installed Internet Explorer 6 on Microsoft PCs. IBM engineers believed Microsoft engineers