if you want an overview of all the know pc's with the last logged on users (and if available the model, IP-address and size of Ram-memory then you can try the following script :
SELECT tblcomputers.Computer, tblComputers.Username, c.Model, s.IdentifyingNumber,tblcomputers.lastknownip, cast(cast(c.TotalPhysicalMemory as decimal(18,2))/1048576 as int) as TotalPhysicalMemory, cast(datepart(dd,c.Lastchanged) as nvarchar(2)) +N'/'+ cast(datepart(mm,c.Lastchanged)as nvarchar(2)) +N'/'+ cast(datepart(yyyy,c.Lastchanged) as nvarchar(4)) as LastChanged
FROM tblComputersystem AS c INNER JOIN
tblComputerSystemProduct AS s ON c.Computername = s.Computername right JOIN
tblComputers ON c.Computername = tblComputers.Computername AND s.Computername = tblComputers.Computername
where tblcomputers.username like '%'
ORDER BY c.model
