If you open the an attachment with the same name for 99 times you will get a message saying can't create file. To correct the problem.
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. Change the # to a different #.
4. Restart Microsoft Outlook and you should be able to open your attachments.
OR
You can remote into the C drive from another computer and delete the files or rename the folder.
\\%omputerName%C$\Documents and Settings\%USER_NAME%\Local Settings\Temporary Internet Files\