A former executive at software giant Microsoft is assuming oversight of the Obama administration's efforts to repair the troubled HealthCare.gov website, the Department of Health and Human Services announced Tuesday. Kurt DelBene, who most recently served as president of the Microsoft Office Division, will take over from Jeffrey Zeints, a management expert whom the president asked to rescue the site after its disastrous rollout on Oct. 1. Zeints is widely credited with helping to make the site functional, allowing tens of thousands of Americans to select a health insurance plan on marketplaces created by the president's 2010 health law.