Question : Unable to open PDF's in Outlook 2007, ""There was an error opening this document. This file cannot be found."

One of our users lost the ability to open PDF's in Outlook 2007 about a week and a half ago.

The PDFs can be downloaded and opened by Adobe Acrobat 9.3 or Adobe Reader. When attemting to open them from within Outlook, the following error message appears:

"There was an error opening this document. This file cannot be found."

Things I have tried:

1. System Restore: I have seen this in the past and using System Restore resolved the issue. On this machine, I have been unable to sucessfully use System Restore.

2. Downloaded Abode Reader 9.3 and associated PDF files with the program. This worked until the next day. The user then informed me that it did not work. I remoted on that evening and was sucessful, yet the following day it did not work. The system did not restart and I could find nothing had changed. Since this point I have had no sucess.

3. Cleared the temp files in outlook.

4. I also repaired adobe acrobat

5. Ran Malwarebytes. While sucessful in finding problems, removing them did not help the PDF issue.

6. Working theory is that the users .ost is to big (7.96 GB) and causing outlook to be unstable. Plan is to archive on Friday.

Any other ideas? Thank you in advance for your help.

Answer : Unable to open PDF's in Outlook 2007, ""There was an error opening this document. This file cannot be found."

After doing the above, I reinstalled Office 2007. The problem still persists. I will be reinstalling the OS. Closing the question.