The report below gives you an overview of all Windows computers and their monitors as requested.
Select Top 1000000 tblAssets.AssetID,
tblAssets.AssetUnique,
tblAssets.Lastseen,
tblMonitor.MonitorModel,
tblMonitor.MonitorManufacturer,
tblMonitor.ManufacturedDate,
tblMonitor.SerialNumber,
Count(tblA.MonitorID) As NrOfMonitors,
tsysAssetTypes.AssetTypeIcon16 As icon
From tblMonitor As tblA
Right Join tblAssets On tblAssets.AssetID = tblA.AssetID
Left Join tblMonitor On tblAssets.AssetID = tblMonitor.AssetID
Inner Join tsysAssetTypes On tsysAssetTypes.AssetType = tblAssets.Assettype
Where tblAssets.Assettype = -1
Group By tblAssets.AssetID,
tblAssets.AssetUnique,
tblAssets.Lastseen,
tblMonitor.MonitorModel,
tblMonitor.MonitorManufacturer,
tblMonitor.ManufacturedDate,
tblMonitor.SerialNumber,
tsysAssetTypes.AssetTypeIcon16