"Run only allowed Windows applications" blocks MS Office URLs

We want users to be able to open hyperlinks from MS Office apps, including mailto: and http:.

If the Group Policy "Run only allowed Windows applications" is set (under User Config | Admin Templates | System), then users opening hyperlinks from MS Office apps (including Outlook, Word, and Excel at least), see the standerd GP restriction error:

        This operation has been canceled due to restrictions in effect on this computer.  Please contact your system administrator.

Admins are NOT blocked, and if I disable that policy, neither are users.  It affects http: and mailto: urls, at least.

I can't figure out what the problem is.  Word, Excel, Oultook, Firefox and IExplore are listed as permitted in the policy and all run fine.  As far as I know, the policy allows any executable called by a permitted executable (this must be true, or I'd see errors everywhere).

I've tried the following; nothing worked.

  * Adding every executable in the MS Office install directory to the policy's whitelist
  * Adding these files to the policy whitelist:  mshtmled.dll, hlink.dll, mshtml.dll.  Filemon showed these being accessed when a hyperlink is clicked
  * Resetting this registry key per MS kb q310049:  HKEY_Local_Machine\Software\Classes\htmlfile\shell\open\command  (though any problem there should affect all users, including admins).
  * Adding "http://www.cnn.com" to the whitelist, then trying that url from Word.

Any suggestions would be much appreciated!
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IntIncAuthor Commented:
I should correct that first sentece (it would be nice if we could edit posts): We want to open links in the default app, whatever it is.  Our mailto handler is Outlook, for example.
How about OLE?
IntIncAuthor Commented:
OLE works fine.  We can link, embed and edit linked/embedded files
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IntIncAuthor Commented:
For anyone's future reference, here's what we found:

The problem only occurred in the following circumstance:
    1)  The 'run only allowed windows applications' group policy was enabled
    2)  Using Microsoft Office 2003 apps (though we didn't try other versions of Office)
    3)  Firefox was the default browser

Note that Firefox worked fine outside of MS Office links.

The solution was a combination of the following:

   1)  MS Office apparently does not use the Windows shell to process hyperlinks, but uses it's own internal process.  MS KB 218153 describes how to force it to use the shell

   2)  In the registry, paths to Firefox were expressed in the short filename format (e.g. c:\progra~1\Mozill~1\...).  It wouldn't work unitl we changed it to long filenames worked.  We don't know why.  We do know that when you set Firefox as teh default browser (firefox | tools | options | ... | set as default), it changes back to the short filename.

   3) The fix in this Microsoft KB article may have been required; it was over a month ago and I don't remember if it was necessary or not:

We found the solution on our own, so we are not awarding points.
Luc FrankenEMEA Server EngineerCommented:
I'll change my recommendation to PAQ/Refund.
Thanks for sharing your solution IntInc.

PAQed with points refunded (400)

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