My setup fails with the message "setup cannot continue because some importanr files are missing". This is on a new HP laptop after I have downloaded the set up application ,exe
Sorry for my reply.
Does it possible that with your fresh HP laptop there pre-installed some security software?
For example, McAfee?
With my own experience - even if it removed/deleted by common steps (designed) - such situation anyway can be as stuck-reason for F-Secure installation.
If there McAfee -> should be useful next their tool:
McAfee Consumer Product Removal
"Related" tools can be with another security softwares too;
If this is not an option (or not useful) -> probably you able to try F-Secure Uninstallation Tool: https://community.f-secure.com/t5/F-Secure-SAFE/F-Secure-Uninstallation-Tool/td-p/31265 ;
And then "else one" try to install F-Secure;
// Good to be sure - that Windows (?) also up-to-dated with latest updates installed;