Continuing last week's spate of executive turnover at Microsoft, Mary Jo Foley is reporting today -- with confirmation from Redmond -- that Robert Short, corporate vice president, Windows Core Technology, is not returning to the company after a year-long leave of absence.

Short, according to his Microsoft bio, leads a team "responsible for the design, development and testing of the core components of the Microsoft Windows operating system: the operating system core, virtual machine technology, input/output subsystems and the core device drivers."

A recent project, the bio continues, "focuses on improving driver quality for all Windows products." I'm guessing a lot of that had to do with getting Windows Vista driver compatibility up to snuff. (Chairman Bill Gates told me recently, "There were some complexities in the ecosystem that we needed to do a better job on in terms of getting the drivers and the upgrade and making that easy. As we put new things online over the course of the year, that's improved a lot, as the manufacturers have done things on their side.")

Short, who holds a master's in computer science from UW, was at Microsoft for 20 years.