Nsf extension file

[KeeK02]

Sorry if this is the wrong place to put this but I need this question answered badly. I urgently need to open .nsf extension file. But LotusNotes cannnot do it....The error message occurs: Unknown file.
Can anyone advise what could have caused this and how can i open this file??

 

[farell000]

Google's search results:
http://www.nsf.repair/
Lotus Notes .nsf repair support site: http://www-01.ibm.com/support/docview.wss?uid=swg21219591