Helvetica Neue browser issue?

I had to install the font for a project, and upon doing so, it messed up the font in my browser, and at times makes it hard to read:


Upon Googling the issue, I've found this solution:

To fix Helvetica Neue in Firefox:
Browse to C:\Users\YOURUSERNAME\AppData\Roaming\Mozilla\Firefox\Profiles\xxxxxxxx.default\chrome

In this folder, edit userContent.css (or create it in notepad if it doesn't exist) and add these two lines:
@font-face { font-family: 'helvetica neue'; src: local('Arial'); }
@font-face { font-family: 'helvetica neue'; font-weight:bold; src: local('Arial'); }

You will need to close firefox and reopen it to see the change.

But I don't even have a chrome folder in my Firefox profile?
Any help/suggestions would be appreciated.