One approach:
SELECT Top 1000000
tblAssets.AssetID,
tblAssets.AssetName,
tsysAssetTypes.AssetTypename,
tsysAssetTypes.AssetTypeIcon10 As icon,
tblAssets.IPAddress,
tblAssets.Lastseen,
tblAssets.Lasttried,
tblSoftwareUni.softwareName
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 Corp%'
AND tblSoftwareUni.softwareName LIKE 'Windows Internet Explorer%'
AND LTrim(Right(tblSoftwareUni.softwareName, 2)) NOT IN ('9', '10', '11')
I don't have any systems on my network with anything lower than IE6, so I can't verify how those will appear, hence my choice to exclude what I can confirm works (9/10/11) rather than explicitly check for 8, 7, 6, 5, etc.