Duncan Reid, former Microsoft UK licensing manager, said: "After 10 very happy years with Microsoft I want to pursue personal interests outside of the IT industry, one of which is an educational welfare project in Sweden for under-privileged children."
Reid refused, however, to dismiss the possibility of returning to the cut-and-thrust of the IT business.
"I would not rule out returning to the IT industry or, indeed, to Microsoft at some point in the future," he said.
"I can absolutely, categorically, say it was my decision to leave Microsoft," Reid added.
Reid faced one of the toughest jobs in IT after the software giant's new licensing arrangements, which were announced in May last year, provoked uproar among UK users. He described rolling out the controversial strategy as "an interesting challenge".