SELECT Top 1000000
tblAssets.AssetID,
tblAssets.AssetName,
tsysAssetTypes.AssetTypename,
tsysAssetTypes.AssetTypeIcon10 As icon,
tblAssets.Userdomain,
tblAssets.Username,
tblAssets.IPAddress,
tblAssets.Lastseen,
tblAssets.Lasttried,
tblSoftwareUni.SoftwarePublisher,
tblSoftwareUni.softwareName,
tblSoftware.softwareVersion
FROM
tblAssets
INNER JOIN tblAssetCustom ON tblAssets.AssetID = tblAssetCustom.AssetID
INNER JOIN tsysAssetTypes ON tsysAssetTypes.AssetType = tblAssets.Assettype
INNER JOIN tblSoftware ON tblAssets.AssetID = tblSoftware.AssetID
INNER JOIN tblSoftwareUni ON tblSoftwareUni.SoftID = tblSoftware.softID
WHERE
tblAssetCustom.State = 1
AND tblSoftwareUni.SoftwarePublisher LIKE 'Microsoft%'
AND tblSoftwareUni.softwareName LIKE '%2003%'
AND tblSoftwareUni.softwareName LIKE '%Office Professional%'
As an alternative to checking for "2003" in the name, you could test for
tblSoftware.softwareVersion LIKE '11.%'