I included a sample report below that lists any active assets without a "used by" user relation. Instructions for adding this report to your Lansweeper installation can be found
here.
Select Top 1000000 tblAssets.AssetID,
tblAssets.AssetName,
tblAssets.Domain,
tblAssets.Username,
tblAssets.Userdomain,
tsysAssetTypes.AssetTypename,
tsysAssetTypes.AssetTypeIcon10 As icon,
tblAssets.IPAddress,
tblAssets.Firstseen,
tblAssets.Lastseen,
tblAssets.Lasttried
From tblAssets
Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
Inner Join tsysAssetTypes On tsysAssetTypes.AssetType = tblAssets.Assettype
Where tblAssets.AssetID Not In (Select Top 1000000 tblAssetUserRelations.AssetID
From tblAssetUserRelations Inner Join tsysAssetRelationTypes
On tsysAssetRelationTypes.RelationTypeID = tblAssetUserRelations.Type
Where tsysAssetRelationTypes.Name = 'used by') And tblAssetCustom.State = 1
Order By tblAssets.IPNumeric,
tblAssets.AssetName