15 Oct

"You may not have the necessary permissions" when installing Firefox


When installing Firefox you get a dialog box stating:

“You may not have the necessary permissions to use all the features of the program you are about to run. You may run this program as a different user or continue to run the program as the current user.”

You are given the option to run as the current user or to run as a different user.


This can be caused if UAC is disabled on Vista or by faulty UAC settings in Windows 7.


Right click on the Firefox install file and click Run as administrator.
(Thanks to suggestions in the comments.)

If that does not work then select the correct tab below for further isntructions:

  1. Click the Start button.
  2. In the Start Search box, type UAC.
  3. Click on ‘Change User Account Control Settings’.
  4. If it is currently set to Default, try setting it to Never Notify (drag the slider to the bottom) and click OK.
  5. If it is currently set to Never Notify, try setting it to Default.
  6. You can also try setting it to Never Notify, clicking OK then going back into it and changing it back to Default.
  7. Once done, try installing Firefox again.
  1. Click the Start button.
  2. Click Control Panel.
  3. In the top right search box type UAC.
  4. ‘Turn User Account Control (UAC) on or off’ will appear. Click on it.
  5. If the checkbox is unchecked then check it and click OK.
  6. It will ask you to Restart. Click Restart Now.
  7. Try installing Firefox again.

77 Responses to "You may not have the necessary permissions" when installing Firefox

  1. or Click with right button on the downloaded firefox and "run as administrator"

  2. Using Vista, I was not able to check my UAC box, but right clicking and running as administrator did the trick.

  3. I was unable to check my UAC box too, but yes, thank you very very much for the “click with right button on the downloaded firefox and “run as administrator”.” – trick!

  4. many thanks.
    works fine

  5. Saurabh Agrawal September 2, 2011 at 17:10

    Step no. #6 above solved my problem… thanks very much…..


  7. Thanks for the help!

  8. Thanks.. 🙂

  9. Thanks very much!

  10. Thank you very much

  11. Thanks it works for me….

  12. Thank you….I tried this way and succeed…

  13. Thank you very much.. My problem was solved..

  14. I was able to re-install Firefox by running as administrator, but now I can’t even open Firefox. At all.

  15. siiiiiiiiiiiiiiiiiiiiiiiiiiiiii c’è l’ho fatta!!! grazie!!!

  16. BIG THANKS!!! Changing to one step higher from never notify solved my problems.

  17. your awesome thank you soooooooo much …

  18. terima kasih

  19. Muchas gracia me ayudo muchissimo

  20. thank yooouuu!!!!

  21. thankkss!! I love you for this!!

  22. Thx.. very much ^_^

  23. Roberto Ribeiro February 5, 2012 at 21:23

    Thank you, my problem was solved too!

  24. Thank you!!!!!

  25. D A N K E – right click hat geholfen !

  26. Thank you very much….:-)

  27. Thank you , my problem solved.

  28. Thank you very much Sir.

  29. Problem solved!!!!!!!!!!!!!!!!I love you!Thx;)

  30. Win 7: once you have changed your user account settings to “never notify” you also need to reboot for the settings to take effect.

  31. adhyt prasetyo March 23, 2012 at 04:38


  32. thank you very much 😡

  33. thank you so much!!!

  34. thanks dear,,,,, I have got the solution!

  35. Thanks!!! I’m french, but this article has been a great help for me ^^


  37. Gracias, me sirvió de maravilla.

  38. thanks alot

  39. thanks for solution

  40. thnk you

  41. ah running program as administrator worked for me thanks

  42. Thank you so much! Excellent instructions. Simple, precise and to-the-point.

  43. dzięki stary 😀

  44. you might be a genius… it works… thanks

  45. THANKU VERY MUCH…………..

  46. thank you very much i solved my problem

  47. Gura mile maith agat. Yet another annoying MS feature circumvented

  48. It’s Work! Thanks friend!!!

  49. Thanks!
    Made my day 🙂

  50. Dear autor, thank you very much for such clear decision of such difficult problem!!!


  52. thanks a lot

  53. thanks a lot !!!

  54. thanks its works

  55. Thanks a lot !!

  56. thnxx it worked….:)

  57. thanks!!!!!!!!!!!!!!!!!!

  58. Many thanks

  59. that works. big thanks for that!

  60. Luis Felipi silva March 17, 2014 at 01:44

    Obrigado amigo ajudou muito eu ia joga um jogo e preciso do firefox valeu Abraço !

  61. Awesome! Thank you!

  62. Muhammad Qaisar Khan November 10, 2014 at 07:24

    I right clicked on file and clicked “run as administrator” and it worked for me.
    Thanks for help

  63. thank you !! your a life saver

  64. Thanx! it work for me!

  65. Thanks!

  66. Right click, run as admin works!! WHY THE HELL DO THEY MAKE IT LIKE THIS!!!!
    I just wasted 30 minutes on the bulls***!! And guys at Mozilla didn’t even know.

    But thanks again!

  67. Running as administrator in Windows Vista worked perfectly, many thanks.

  68. Thanks!

  69. Thankx alot bro…
    It realyy worked
    God Bless U !!!


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