F Secure Booster - windows error message following automatic update


Have been using F Secure Booster since mid May 2015 without any issues and have found the programme very useful and efficent.  However an automatic update undertaken today has rendered the programme unusable as it will not run, instaed I am presented with a Windows error message as follows - 'the programme cannot start because mfc120u.dll is missing from you computer'.

Is there a fix, as I am concerned if I unistall the programme I may not be able to reinstall without repurchasing as my autorisation code was used on the initial installation? 

Thanks, stph 


  • stph
    stph Posts: 2

    Thank You, Simon I took your advice and downloaded the Microsoft programmes and they appear to have fixed the problem as F Secure Booster is up and running again.


    Thanks again,


  • ianorion
    ianorion Posts: 4 New Member



    ive tried that but still not working



  • Simon
    Simon Posts: 2,667 Superuser
    Hi Ian,

    Not sure what else to suggest, as that seems to be the common fix for the mfc120u.dll error. Did it install correctly, and have you tried a reboot since installing the fix?
  • [Deleted User]
    [Deleted User] Posts: 0 Former F-Secure Employee

    Hello ,


    This is usually caused by a wrong or corrupted C++ Redistributables  installation.

    To correct the problem please proceed as follows:

    -Start vcredist_2013_x86.exe located under C:\Program Files (x86)\F-Secure\F-Secure Booster\  

    -Install it 

    -If you get the question "install or repair", please choose repair. 


    After this step it should work.

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