Create a new collection, and select a Query based rule
Give the rule a name, limit it to a collection if you wish. Click "Edit Query Statement..."
On the Query Statement Properties, click "Show Query Language". This will allow you to enter a statement rather than selecting fields manually.
Paste in the the query below, and change the <OSVERSION> with the version number below that.
select SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,SMS_R_SYSTEM.Client from SMS_R_System where SMS_R_System.OperatingSystemNameandVersion like "%<OSVERSION>%"
Windows XP: Workstation 5.1
Windows 7: Workstation 6.1
Windows Server 2003: Server 5.2
Windows Server 2008: Server 6.0
Windows Server 2008 R2: Server 6.1
Save the query and the collection. Update and the collection will now contain all machines that have reported to be running that OS Version.
