x64 and x86 machines in System Center 2012

For x86 machines make a query:

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 inner join SMS_G_System_COMPUTER_SYSTEM on SMS_G_System_COMPUTER_SYSTEM.ResourceID = SMS_R_System.ResourceId inner join SMS_G_System_OPERATING_SYSTEM on SMS_G_System_OPERATING_SYSTEM.ResourceID = SMS_R_System.ResourceId where SMS_G_System_COMPUTER_SYSTEM.SystemType = "X86-based PC"

For x64 machines make a query:

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 inner join SMS_G_System_COMPUTER_SYSTEM on SMS_G_System_COMPUTER_SYSTEM.ResourceID = SMS_R_System.ResourceId inner join SMS_G_System_OPERATING_SYSTEM on SMS_G_System_OPERATING_SYSTEM.ResourceID = SMS_R_System.ResourceId where SMS_G_System_COMPUTER_SYSTEM.SystemType = "x64-based PC"

Source:
https://social.technet.microsoft.com/Forums/systemcenter/en-US/3591397c-157e-40ce-b3f4-9d304efa21ac/sccm-querycollection-windows-7-x64?forum=configmgrgeneral