Accessing Shared Folder Using Oracle Database
To troubleshoot this type of erro follow the steps bellow :


1- make sure that the location where you want to write exists.
2- make sure that the oracle(or the user who runs the database instance) user has the right to write in that
location.(try to create txt file in that location as Oracle user.)


Ok , more steps for you to troubleshoot:
- i see you are running Oracle on Windowzzz! Correct ?
 Go to your Services tool and see who(what account) is running the Oracle services, form here make sure this user has access to the directory where you what to write to!  

Now maybe is better for you to write into another location(your user home directory):

SQL&gt; CREATE pfile='C:\Users\user.name\Downloads\pfile' FROM spfile;



if the error persists then your problem is different ! 
From this point you can think of security baselines etc...