Nickfile (NK2) file format is used by Microsoft Outlook to store contacts and e-mail address aliases. It is also known as Nickname file or Outlook AutoComplete file. Nickname list is maintained by MS Outlook which is used by automatic name checking feature. When you use MS Outlook, the nickname list is automatically generated. When you compose a new message, a list of contacts is generated to which you have contacted with so you can choose any contact from the list. In Outlook 2010, nickname file is stored on Microsoft Exchange. When you use MS Outlook 2010 and 2013 for the first time, your default message store imports the nickname cache into a hidden message.
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Nickname cache may get corrupted and this could have serious effects on Outlook such as it may send message to wrong person, unable to specify recipients and it may provide wrong recipients when completing the e-mail address automatically. However, you can recover your Nickname file through a manual way. But before following the steps given below, you need to install MS Outlook application on your system and download and extract NK2.info to desktop:
- Create Backup of your NK2 file: Close Outlook application (if running) on your system. Go to Run window, type %userprofile%\Application data\Microsoft\Outlook and press enter. Now, copy .nk2 file to your system’s desktop.
- Export fields from .nk2 into CSV file: Start NK2.info application. Click on browse andlocate the NK2 file. Contact list and email addresses will be recovered from the NK2 file. After that, click on Export Now and Close.
- Import CSV data into Contacts folder of MS Outlook:
- Open MS Outlook application and switch to folder view.
- Right click on Inbox folder and click on New Folder. From the drop down list of Folder Options, choose Contact Items.
- Give a name to the folder and click on OK. A new folder will be created.
- Now select file and click Import. Select “Import from another program or file” from the list and then click on Next.
- Then, select “Comma Separated Values (Windows)” and click on Next.
- Locate nk2.info.csv file an click on Next
- Select new folder, click on Next and then click on Finish
- Rename NK2 file: Open Run window and type %userprofile%\Application data\Microsoft\Outlook and press OK. Then, rename outlook.nk2 to outlook.old and open MS Outlook.
- Import NK2 Recovery contacts and recreate auto complete file:
- Disconnect from the network and disconnect MS Outlook
- Select all the contacts and copy from new contact folder
- Click on New Mail and paste the contacts in ‘TO:” text box and then Send
- Select Outbox and delete the sent email.
- To test the auto complete feature, compose a new mail and type letters
- You can delete the new contact folder which you have created if everything is working. Make sure that there is no email in Outbox
- Finally, reconnect your system to the network.
This manual way may work in some cases and in some cases it might not work because of the high corruption level. NK2 file is prone to corruption, so it may get corrupted. But you can try third-party solution if the above manual solution doesn’t work. One of the trusted third-party solutions is of SysInfoTools Outlook Cached Contacts Recovery software. It is capable of recovering contacts from corrupt .nk2 file and save it to both VCF and CSV format. You can download its demo version which is freely available on its website.