It is mandatory to have any version of MS Outlook and Lotus Notes installed in your system.
How to Install and Configure Lotus Notes?
How to Install and Configure MS Outlook Client?
After downloading the SysTools NSF Converter software you can install it in any folder. After installing the software you become enable to perform NSF to EML and NSF to MSG Migration by following very simple step given here
• Open SysTools NSF Converter tool by clicking on Start Menu (Home Menu) >> All Programs >> SysTools NSF Converter >> SysTools NSF Converter:

• Now start the process by browsing the NSF files from the source point, Click on Browse (software has ability to search NSF files in sub folder also).

• Now following screen will display with all the list of NSF files stored in selected folder (source).

• Next step is to provide destination location path, click on Browse.

• According to user choice, you can tick MSG format or EML format

With category option user according to their choice exclude or include different category for conversion according to their preference.
Now if you want to maintain the same Folder Hierarchy i.e. keeps the same order of the folder which was there in your previous Email Client, Click on the check box visible in software.

• Simple, click on Start Conversion button resolve each and every email conversion problem of user.

• Now, the email conversion process is on, user can see their file converting process live.

• Conversion done successfully message will directly appear on screen after NSF converter tool migrate NSF messages into EML/ MSG format.

Double clicking Outlook PST file won't help you in accessing its contents. Read on how you view generated PST data here at How to Outlook Guide