I can not open some pdf attachment in Outlook. I can open them in OWA (WEB
MAIL). I use Adobe Reader 7.0 and Acrobat 5.0. It only occurs with
documents created by a particular proprietary software. All other Adobe
documents are fine. I use Outloook 2000 (9.0.0.2711) for Internet Mail Only.


I have tried using this fix listed below but it does not work for me. I can
not locate the "OutlookSecureTempFolder" using the regedit.exe

From http://www.send2fax.com/kb.asp

Outlook 2000, XP, and 2003
====================
Can't Open PDF or TIF Attachments
You may receive the following error message when opening attachments in
Outlook (such as PDF faxes):

"Can't create file: ***.pdf. Right-click the folder you want to create the
file in, and then click Properties on the shortcut menu to check your
permissions to that folder"

Microsoft Outlook uses a temporary folder to save and open the attachments.
By default that folder is hidden and the only way to locate it is to look in
the Registry:
Open REGEDIT.EXE and go to Edit - Find... In the Find dialog box type
"OutlookSecureTempFolder" without the quotes and locate that registry key.
That key will contain the actual folder location, and will look like:
C:\Documents and Settings\%USER_NAME%\Local Settings\Temporary Internet
Files\OLK#\ (where # is a random letter or number)

Copy the location of that folder.

Click on Start Run ... and paste the folder location from step #4 then
click OK.

Windows Explorer will open that folder. Please delete all files present.

Restart Microsoft Outlook and you should be able to open your attachments.