Editor in SQLPLUS gives error when changing default editor

Question

Recently, I was told by the security team at work that I had to remove vim from my computer. I have used vim for years as my default editor in SQLPLUS. I decided to change to using notepad++. I modified the "define _editor" line in my login.sql file, but when I'm using SQLPLUS and type in 'ed', I get the message 'C:\Program' not recognized as an internal or external command. I even added the directory that contains notepad++.exe to my system path, but still no luck. Any ideas?