a year's worth of sales, Vista logged less than half the vulnerabilities that Windows XP did in its first year.
Microsoft report author Jeff Jones, who is Security Strategy Director in Microsoft’s Trustworthy Computing group, said that Vista came out ahead of all of the other first-year OSes, including Windows XP, Red Hat rhel4ws, Ubuntu 6.06 LTS and Apple Mac OS X 10.4.
Microsoft released 17 security bulletins and patches affecting Vista, versus 30 for XP in its first year. Redmond fixed 36 vulnerabilities in Vista, versus 65 for XP.
There are 30 vulnerabilities in Vista that have not yet been patched, and 54 for XP in its first year.