PC with Windows 10 x64 on Ryzen 7 1700, was using the latest Firefox version. After visiting website nicehash.com, I have downloaded and executed their autodetect system tool. Firefox was working fine. Then I have downloaded their utility of coin mining and tried to install it. Comodo security immediately warned me about an issue of the software (was trying to modify registry key probaby) and I have blocked it and terminated it. Since then, Firefox won't browse any website, won't close after clicking the X button on the upper right corner, (exiting it only with right clicking on the icon on the taskbar) in general won't operate. I have tried uninstalling it/clean re-installing it, refreshing it, deleting the Mozilla directory from Program Files before doing it and still the same problems. Chrome browser is working fine. Unfortunately system restore to an earlier state won't succeed. Scanning with Eset's NOD32 antivirus won't show any viruses. A help on this would be appreciated because I'm on a dead-end on this.