+ 0 Votes Question jisch 6 years ago Did you find an answer to this problem yet? I am really curious as we have a machine with this same problem. jisch at tampabay dot rr dot com + 0 Votes Try this... Use Cached Exchange Mode larahs 6 years ago This problem started appearing after I installed some Office 2003 patches via Windows/Office Update. Tried deleting profile - didnt work. Tried clearing temp - didnt work. Tried disabling addins - didnt work. Instead... enabled "Use Cached Exchange Mode" in profile. YES, YES, YES... no more "The Operation Failed" error messages. Apparently, this is an issue for slow networks or Exchange server responses. + 0 Votes Help!!! tkobal 6 years ago did anyone find a resolution to this? + 0 Votes Clean temp files ThumbsUp2 Updated - 6 years ago Warning.... do not attempt this if you don't know what you're doing. Messing up the registry can render your computer useless. Outlook uses a temporary folder to store attachments when you open them. However, each time you open them it creates another file and never cleans up after itself. Consequently, the folder gets full. Once it has 99 copies of the same named file in it, you will experience problems opening the file from within Outlook (versus saving to your hard drive and opening from there). Microsoft posted this as help for file attachment problems. I can't find the specific link to it now, but this is how the article read: 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: 1. Open REGEDIT.EXE and go to Edit -> Find... In the Find dialog box type "OutlookSecureTempFolder" without the quotes and locate that registry key. 2. 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) 3. Copy the location of that folder. 4. Click on Start -> Run... and paste the folder location from step #4 then click OK. 5. Windows Explorer will open that folder. Please, delete all files present. 6. Restart Microsoft Outlook and you should be able to open your attachments.