If you want to add the user logged in when the computer was last scanned, then you can try this report:
Select Top 1000000 tblAssets.AssetID,
tblAssets.AssetUnique,
tblAssets.Domain,
tsysOS.OSname,
tblSerialnumber.Product,
tblSerialnumber.ProductID,
tblSerialnumber.ProductKey,
tsysOS.Image As icon,
tblAssets.Username,
tblAssets.Userdomain,
tblADusers.Displayname,
tblAssets.AssetName
From tblAssets
Inner Join tblSerialnumber On tblAssets.AssetID = tblSerialnumber.AssetID
Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
Inner Join tsysOS On tblAssets.OScode = tsysOS.OScode
Left Join tblADusers On tblAssets.Username = tblADusers.Username And
tblAssets.Userdomain = tblADusers.Userdomain
Where (tblSerialnumber.Product Like '%windows%' Or
tblSerialnumber.Product Like '%microsoft%office%') And
tblAssetCustom.State = 1
Order By tblAssets.AssetName,
tblAssets.AssetUnique,
tblSerialnumber.Product