@zaibon @Ayespy Congrats! It looks like Avast! was indeed the main problem. I unistalled Avast!, using Avast Uninstall Utility, and it did change the overall speed of my computer (way faster now). Vivaldi, with several tabs + extensions + all the history data is now starting in ~8 sec. I am having a look at Avira, to see if it could be a better solution for my computer. Thank you very much for your help!