The following report (similar to the built-in report "
Computer: Encryptable Volumes") lists laptops not having Bitlocker enabled:
Select Top 1000000 tsysAssetTypes.AssetTypeIcon16 As icon,
  tblAssets.AssetID,
  tblAssets.AssetName,
  tblEncryptableVolume.DriveLetter,
  Case When tblEncryptableVolume.ProtectionStatus = 0 Then 'OFF'
    When tblEncryptableVolume.ProtectionStatus = 1 Then 'ON' Else 'UNKNOWN'
  End As ProtectionStatus,
  tblEncryptableVolume.LastChanged
From tblEncryptableVolume
  Inner Join tblAssets On tblEncryptableVolume.AssetId = tblAssets.AssetID
  Inner Join tsysAssetTypes On tblAssets.Assettype = tsysAssetTypes.AssetType
  Inner Join tblPortableBattery
    On tblAssets.AssetID = tblPortableBattery.AssetID
Where tblEncryptableVolume.ProtectionStatus = 0