Windows Update Temporary Folder location

Windows Update (and for all I know other MS Update services) appears to download to a temporary folder in the root of the drive with the most free space at the time of the download.

This may be OK for the average PC but is not good practise on servers where the drive with the most free space may be on a SAN or on a non-NTFS formatted drive.

Is there any way of steering the Update service to restrict itself to local drives or even better to specify an exact path for the temporary download folder.

I have been searching the internet for an answer to this but so far drawn a blank. I'm hoping this might be the forum with an answer.

Thanks - Bill