After four years at the helm of Microsoft\u2019s security group, Mike Nash is taking a break. This June he will go on sabbatical after handing over responsibilities to his replacement, Ben Fathi.Nash led Microsoft\u2019s Security Technology Unit during a period in which the security of Microsoft\u2019s products was increasingly scrutinized following a number of worldwide worm attacks, including Slammer and MyDoom.The 15-year Microsoft veteran was responsible for directing Microsoft\u2019s response to these threats as well as for setting its overall security strategy as the software vendor struggled against a public perception that its products were insecure.Nash\u2019s departure was announced Thursday as part of a sweeping reorganization of the company\u2019s Platforms & Services Division.Fathi comes from Microsoft\u2019s storage division, where he managed the company\u2019s Windows file server, NAS (network-attached storage) and branch office businesses. As Nash\u2019s replacement, he will report to Brian Valentine, head of Microsoft\u2019s Core Operating System Division.A Microsoft employee since 1991, Nash was the first product manager for Windows NT, and at one time he oversaw the Microsoft.com website. He is expected to return to a new position at Microsoft sometime later this year,\u00a0a spokeswoman said.-Robert McMillan, IDG News ServiceFor related news, read Microsoft Restructures Windows Unit and Report: Sinofsky to Take Over Windows Team.This article is posted on our Microsoft Informer page. For more news on the Redmond, Wash.-based powerhouse, keep checking in.Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.