I've found that the fastest browser in Windows 10 is IE....I know, unbelievable! Firefox is slow to open and Chrome struggles to open. Firefox takes anywhere from 3 to 10 seconds to open up using default settings and now addon's. Chrome on the other hand takes anywhere from 5 to 20 seconds to open, again default settings and no addon's. Where as IE 11 damn near opens instantly....I must say it's a bit refreshing to see it preform so well.