Outlook.exe.log file in the %Temp% folder consumes too much disk space

Original KB number:   3038305

Symptoms

In your computer's %Temp% folder, you notice a very large file (for example, more than 1 GB) that's named Outlook.exe.log.

Note

The %Temp% folder is typically found at C:\Users\<user name>\AppData\Local\Temp.

Cause

This problem may occur if you turned on TCOTrace logging by enabling the following registry settings:

Key: HKEY_CURRENT_USER\Software\Microsoft\Office\x.0\Common\Debug
DWORD: TCOTrace
Value: 1

Note

The x.0 placeholder represents your version of Office (16.0 = Outlook 2016, Outlook for Office 365 and Outlook 2019, 15.0 = Outlook 2013, 14.0 = Outlook 2010, and 12.0 = Outlook 2007).

TCOTrace logging should remain enabled only as long as you are working with a support engineer on a specific issue.

Resolution

To resolve this issue, follow these steps:

  1. Exit Outlook.

  2. Open a Run dialog box. To do this, use one of the following methods, as appropriate for your situation:

    • Windows 10, Windows 8.1, and Windows 8: Press Windows key+R.
    • Windows 7 or Windows Vista: Select Start, and then select Run.
  3. Type regedit.exe, and then select OK.

  4. Locate and then select the following subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Office\x.0\Common\Debug

    Note

    The x.0 placeholder represents your version of Office (16.0 = Outlook 2016, Outlook for Office 365 and Outlook 2019, 15.0 = Outlook 2013, 14.0 = Outlook 2010, 12.0 = Outlook 2007).

  5. Right-click TCOTrace, and then select Delete.

  6. When you are prompted to confirm the deletion, select Yes.

  7. On the File menu, select Exit to exit Registry Editor.

  8. Delete the Outlook.exe.log file from the %Temp% folder if you are not working with a Microsoft support engineer on an issue.