Outlook email address auto-fill storage file (nk2) location

I've noticed a few people landing on my blog using search terms that involved finding the nk2 file for Outlook, so I thought I'd post the answer for you. First off, it's hidden, so you need to start by showing hidden files and folders on your computer. You can accomplish this the same way in both XP and Vista:

Open up My Computer, then go to Tools->Folder Options (you may need to press the Alt button in Vista to get the Tools menu to show up). Then go to the View tab, then under Hidden Files and Folders, select "Show hidden files and folders".

Now you can go to the nk2 file, which is in different locations in each OS (Vista and XP)

For XP, you can find it at C:\Documents and Settings\"username"\Application Data\Microsoft\Outlook\

In Vista, it's at C:\Users\"username"\AppData\Roaming\Microsoft\Outlook

If you have multiple nk2 files, it's because you have multiple Outlook profiles. The nk2 for each profile will be named the same as the profile. If you're moving the nk2 file to a different machine, make sure that after you copy it to the new location, you rename the copied nk2 file so it is named the same as the new profile as Outlook relies on that naming convention in order to open and use the nk2 file with a certain profile. The default profile name is Outlook. For the Microsoft instructions, check out this page.