change into this:
Select tblComputers.Computername, tblComputers.ComputerUnique,
tblComputers.Domain, RTrim(tblOperatingsystem.Caption + ' ' +
tblOperatingsystem.OtherTypeDescription) as OS, tblOperatingsystem.OSType
From tblComputers Inner Join
tblOperatingsystem On tblComputers.Computername =
tblOperatingsystem.Computername