The Microsoft introduced NK2 files in Outlook 2002 and later versions to provide users with a suggestion of contacts when user type a name of or its initials. This file sometimes called as Nick(.nk2) file extension.

NK2 File Format belongs to a category of Contacts, Email messages, and address category.

All Microsoft 2002 and above versions (that is 2003, 2007, 2010, 2013) support .nk2 file extension

Microsoft Corporation

Not Specified

NK2 file format belongs to Email, Names, Address and Contacts type.

Hexadecimal Signature: 0D F0 AD BA 0A 00 00 00

The Location of NK2 File Vary according to different versions of Outlook and Windows

For Outlook 2003 and 2007

• In Windows 2000, XP and Server 2003
  • C:\Documents and Settings\[User Profile]\Application Data\Microsoft\Outlook
• In Windows Vista, 7 and Server 2008
  • C:\Users\[User Profile]\AppData\Roaming\Microsoft\Outlook

For Outlook 2010 and 2013

• In Windows XP
  • C:\Documents and Settings\[User Profile]\Local Settings\Application Data\Microsoft\Outlook\RoamCache
• In Windows Vista, 7 and Server 2008
  • C:\Users\[User Profile]\AppData\Local\Microsoft\Outlook\RoamCache

NK2 files can be opened in two ways

• Outlook 2002 and below versions
• If NK2 files are corrupt then it can be opened using tools mentioned below