Sysinternals - Streams access is denied error

I am using streams.exe to remove blocking of game by Windows but it is showing me "Access is denied" error although I am running the command with administrator.

Article (that one I am following) : http://darrenmyher.wordpress.com/2007/03/22/how-to-permanently-unblock-files-that-came-from-the-internet-sysinternals-streams-utility-zones-vista-and-blocked-files-in-ie/

I wanted do the same: mass-deletion of "Zone.Identifier" alternate data streams (ads) that were attached to 95 downloaded PDF files.

The manual way in windows explorer works only file by file by using the Unblock button in Properties dialog, and so would mean 95 times mouse clickery. Not very feasible, so I tried several utilities …

What did not work:

• "streams.exe" by SysInternals.com shows "Access is denied". Running it in an elevated cmd.exe did not help, either.
• "ADS Spy 1.11"by bleepingcomputer.com shows "The following ADS streams could not be deleted. They may by locked by another program".
• "ADS Scanner 2.01" by pointstone.com shows "stream could not be deleted".

I couldn't find any locks. Even quitting the explorer process and then trying again did not help.

What DID work:

• "UVK - Ultra Virus Killer" by carifred.com: the included "Alternate Streams Manager" was able to delete all 95 Zone.Identifier ADSes in one go.

I've no idea why the other tools failed (and I'd still like to know!), but at least this is a solution.