This is the sort of thing Mac users are all too familiar with, but for users of the dominant Windows operating system, today's bumper crop of security updates will come as a bit of a surprise, in terms of both volume and severity.

Today, Microsoft will issue 13 security updates that cover 34 separate vulnerabilities in various versions of Windows and other products, 8 of which are rated critical. Most alarmingly, there is at least one critical vulnerability in every modern, supported version of Windows, up to and including Windows 7. (Microsoft notes that critical vulnerabilities are those that can lead to remote code execution.) One IE-related update actually applies to Internet Explorer 6, 7, and 8 running on Windows 2000, Windows XP, Windows Server 2003, Windows Server 2008, Windows Vista with SP1, Windows Vista with SP2, and Windows 7 (both 32-bit and 64-bit).

Prior to this month's scheduled security update package, the worst month for Microsoft security updates came in June 2009. Then, the software giant shipped 10 updates covering 31 vulnerabilities.

This month's security updates will be delivered via Windows Update, Microsoft Update, Automatic Updates, and other means beginning sometime later today