Heh, no prob. I'm desktop support, and didn't know any SQL up until a few months ago. To add info from another table, simple nest another SELECT into the statement :
SELECT DISTINCT TOP (100) PERCENT Computername, Manufacturer, Model, NumberOfProcessors,
(SELECT DISTINCT Domain
FROM dbo.tblComputers
WHERE (Computername = dbo.tblComputersystem.Computername)) AS Expr1,
(SELECT DISTINCT CurrentClockSpeed
FROM dbo.tblPROCESSOR
WHERE (Computername = dbo.tblComputersystem.Computername) AND (DeviceID = 'CPU0')) AS expr2
FROM dbo.tblComputersystem
I had to put in the DeviceID= 'CPU0' because it will return multiple values for multi-core/multi-CPU systems, which would result in having the same error as before. The number of processors comes from tblComputerSystem.