Working with the Auto-Complete Cache

Nevertheless, users expect their cache to be manageable so let’s dive in and look at what can be done with this.

The cache itself is implemented in the form of a file that has the .NK2 extension and is named after the name of your outlook profile. By default, this name is likely going to be “outlook.nk2”, but be aware of other names. In Vista and Windows 7, you will find this located at:

“C:\ Users\UserName\AppData\Roaming\Microsoft\Outlook”

in Windows XP

“C:\ Documents and Settings\UserName\Application Data\Microsoft\Outlook”

In order to see this file, you will have to ensure that you have enabled the display of hidden files and folders.  (Learn how:Show Hidden Files)


So, once you have the directory open, it is likely that you will not see an auto-complete cache in that folder. Outlook only creates this after an email is sent and Outlook is closed and re-opened, so go ahead and send a test message to yourself, or whoever you see fit. This will cause an entry to be written to the .NK2 when Outlook is closed and reopened. After doing this, ensure that Outlook remains closed as having Outlook open will put a lock on this file and prevent you from renaming it.

Now, take not of the name of the new .NK2 file. You will have to find the previous one from the old profile, move it to the new directory and rename it to the exact name of the new .NK2 file you have created. Go ahead and rename the new one to profilename.bak. Rename the old .Nk2 file to the name of the newly created one. Finally, reopen outlook and you should have all of the old auto-complete entries available.

Now, given this information, one of the easiest ways of creating a brand new .NK2 cache should the old one be corrupt, is to simply follow the procedure above and just rename the .NK2 file.

Another useful tidbit, is that individual entries in an an auto-complete cache can be deleted by simply hovering over the entry in the drop down and pressing the delete key while it is highlighted.


In Outlook 2010, Microsoft has also added a red X with which you may delete the entry by clicking on it. You can also get a brand new cache in Outlook 2010 by using the Outlook.exe /CleanAutoCompleteCache switch. Simply cut and paste this into the run box and you will end up with a brand new cache.

If you need more extensive editing capabilities of the .NK2 cache there are several free and relatively cheap editors out there that will allow the import of entries and correction in an easy to use editor.

So don’t worry about finding a pair of overalls just yet for your new career, there really are ways of dealing with the auto-complete cache.  I hope this little tutorial helps!



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: