Microsoft Outlook creates a Temporary or OLK folder where it stores attachments opened while reading emails. Here’s how to find it and your lost attachments.
Where does Microsoft create the Outlook Temporary folder (better known as the OLK folder)? Or, where does Microsoft store that pesky OLK folder and temporary data such as attachments?
Depending on the operating system, version of Outlook, and user currently logged in, the OLK temporary folder gets created in a different spot. The good news is, it’s simple to find no matter the version of Outlook including Outlook 2010, Outlook 2013, and the latest Microsoft version, Microsoft Outlook 2016 (including O365).
To determine the spots where folders got created, open the Windows registry using regedit.exe and look for the Registry key OutlookSecureTempFolder using the map below:
Outlook 97: HKEY_CURRENT_USER\Software\Microsoft\Office\8.0\Outlook\Security Outlook 98: HKEY_CURRENT_USER\Software\Microsoft\Office\8.5\Outlook\Security Outlook 2000: HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Outlook\Security Outlook 2002/XP: HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Security Outlook 2003: HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Security Outlook 2007: HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Security Outlook 2010: HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Security Outlook 2013: HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Security Outlook 2016: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Security
Using the chart above, here are a few screenshots comparing my Windows XP system running Office 2003 vs. my Windows 8.1 system running Office 2010.
It’s easy to track down your OLK folder as long as you follow the registry map outlined in the table above. For example, on my Windows 8.1 system running Microsoft Office 2016, I found the OLK temp folder at:
Background – What is the OLK folder, and why is it so hard to find?
When you open file attachments that are considered safe, Outlook places these attachments in a sub-directory in your Temporary Internet Files folder. As Outlook does this, it first examines the registry to determine if the OLK folder already exists. If yes, it drops the files into that folder.
If no, it creates one. When Outlook first copies attachments to a temporary file, it examines the registry to find the path for the TEMP OLK folder. If it doesn’t exist, it creates the registry with a random name then it creates the folder.
Let’s say your running Windows XP and Outlook 2003. When you open your first attachment, your computer will create the following sub-folder to store that attachment temporarily:
C:\Documents and Settings\username\Local Settings\Temporary Internet Files\OLKxxx
In this example, the name of the currently logged-in user would replace the username and the xxx is a randomly generated sequence of letters and numbers.
This information can be very useful. For example, let’s say you open an attachment, make a bunch of changes then close it before you have a chance to save it, or your PC crashes. The good news is you can probably find the file in the Outlook Temporary OLK folder and recover your work. Speaking of recovering your data, have you configured the Word and Excel autosave feature?
Now the bad news
Let’s say you open an attachment that contains sensitive or confidential information. While reading the document, Outlook unexpectedly closes. In this scenario, the attachment will remain in the Outlook Temporary folder indefinitely since Outlook normally deletes these files when you close the document correctly. Now let’s say your PC is lost or stolen. Yup, all your documents are just sitting there for anyone to open.
Don’t think this is very common? Just look. No really. Stop reading and look in your OLK folder. If you’ve been using your computer for any length of time, what you will find is a few dozen files sitting there for anyone with access to your system to open and read.
Protect yourself against the OLK folder
The first thing I always do with new installs of Windows and Microsoft Office is to encrypt the OLK folder using the built-in Microsoft file and folder encryption called EFS. It’s fast, easy and adds a nice layer of security should a corporate IT guy jump on my box or I accidentally lose my laptop, and I haven’t yet encrypted my drive. Now, if you’re using a home PC and don’t have IT guys managing your system, you’re probably okay with just Wiping your system if you sell it, or swap out your hard drive for a faster SSD drive.