I've built the report below to search for Windows desktops and servers scanned in the last 7 days that were not running the "ccmexec" service.  This works very well, but I'd also like to include any systems that did not allow our global credentials to scan.
There's a built-in report called "Error: WMI access denied", which provides exactly this information.  I'm certainly willing to learn a new trick here, but I haven't enough SQL experience to figure this out on my own.  How can I successfully combine the two into a single report?
Select Top 1000000 tsysOS.Image As icon,
  tblAssets.AssetID,
  tsysIPLocations.IPLocation,
  tblAssets.AssetName,
  tblADusers.Displayname,
  tblAssets.IPAddress,
  tsysOS.OSname,
  tblAssets.Lastseen
From tblAssets
  Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
  Inner Join tsysOS On tsysOS.OScode = tblAssets.OScode
  Inner Join tsysIPLocations On tsysIPLocations.LocationID =
    tblAssets.LocationID
  Inner Join tblADusers On tblAssets.Username = tblADusers.Username
Where tblAssets.AssetID Not In (Select tblServices.AssetID
  From tblServices Inner Join tblServicesUni On tblServicesUni.ServiceuniqueID =
      tblServices.ServiceuniqueID
  Where tblServicesUni.Name = 'CcmExec') And tblAssets.Lastseen > GetDate() - 7
  And tblAssetCustom.State = 1
Order By tsysIPLocations.IPLocation,
  tblAssets.AssetName