Need to disable Private Window/Private Browsing on our work computers, both mac and pc?

Question

I support both macs and pcs with version 26 of firefox on all machines. I need to disable private window and private browsing, including the keyboard shortcuts.

Answer 1

Thank you for the info.
I did run across in my searching another way to disable by creating a txt file (userChrome.ccs) with this code, minus the first sentence: (Open the file on any text editor. Copy and paste the following lines after @namespace
/* Hide Private Browsing in App menu and Tools menu */
#appmenu_privateBrowsing, #privateBrowsingItem {display:none!important;}
/* Hide Sanitize item in App menu and Tools menu */
#appmenu_sanitizeHistory, #sanitizeSeparator, #sanitizeItem {display:none!important;}
I need to try it on my mac before I implement it on other macs and the pcs. The directory placement area was a little vag so I tried it here.
I placed the file in: HD/Users/{me}/Library/Application Support/Firefox/chrome
restarted firefox. Did not work.
Does any one know if the above into is correct and if I placed it in the correct area on the mac?
This is the info I got to place the same file on the pc:
C:\\Users\\[User]\\AppData\\Roaming\\Mozilla\\Firefox\\Profiles\\[random string].default\\chrome\\
Does anyone know if this is correct? I can not test this until after hours on the pc.
Thank you again! I really tried to do the research before I posted the question.