Microsoft (opens in new tab) reported that Vista has had much less vulnerabilities than Windows XP and Open Source competitors like Linux.
The author of the report though was quick to admit that the figures do not indicate that Windows Vista was inherently more secure than other Operating systems and should be considered "only within their context".
The Redmond-based company published a paper which showed that Vista was hit by half as much vulnerabilities compared to Windows XP, with 66 bugs discovered between November 2006 and November 2007 and nearly half of them, still un-patched.
Windows XP, on the other hand, saw a barrage of vulnerabilities: 129 of them, out of which 54 were not solved by November 2007.
Jeff Jones (opens in new tab), Microsoft's Trustworthy Computing Security Strategy Director and author of the document, also found that Vista's different approach to Patch Management meant less work for system administrators compared to Windows XP.
Austin Wilson (opens in new tab), a director in Microsoft's Windows client group, mentions two features - Running as a Standard User and Internet Explorer's Protected Mode - that helped in reducing the burden on Sysadmin and make Vista inherently more secure.