Try this:
Select Top 1000000 tblAssets.AssetID,
tblAssets.AssetName,
tblSoftwareUni.softwareName As Software,
tblSoftwareUni.SoftwarePublisher As Publisher,
tblSoftware.softwareVersion As Version,
tblSoftware.Lastchanged,
tblAssets.Lastseen
From tblAssets
Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
Inner Join tblState On tblState.State = tblAssetCustom.State
Inner Join tblSoftware On tblAssets.AssetID = tblSoftware.AssetID
Inner Join tblSoftwareUni On tblSoftwareUni.SoftID = tblSoftware.softID
Inner Join tsysAssetTypes On tsysAssetTypes.AssetType = tblAssets.Assettype
Where tblAssets.OScode Like '%s' And tblState.Statename = 'Active'