Notes about the NK2 file extension:
To open this file type, a required software must be installed. Without it you only see a Windows message "The following file cannot be opened
" (Windows 7) or "How do you want to open this file?
" (Windows 10) if you double-click the file. There click on "More apps"
and choose a suitable software to view such files on your PC or from email attachments.
The NK2 file type is primarily associated with 'Outlook' by Microsoft Corporation. A data file (normally hidden) that contains data Outlook needs to automatically fill in data for you. If you need to delete it to allow Outlook to recreate it (as when Outlook gets confused by changed addresses) it's in the C:\Documents and Settings\Username\Application Data\Microsoft\Outlook directory which is normally hidden. The file may also have your profile name as its rootname.
Detailed information for file extension NK2:
Hex: 0D F0 AD BA 0A 00 00 00
'Identifying characters' used on FILExt.com are
provided by Marco Pontello from his TrID database
To change file associations press Windows Key
and then Apps and Features
> Default apps
> Choose default apps by file type
Invalid file associations could be the result of underlying issues within your Windows PC.