Had a 'stuck on finalizing part of the Minecraft Launcher' problem, then tried reinstalling but somehow can't open the launcher now.

Hello, i'd like to report a problem. I'm very sorry if i'm doing anything wrong, it's because i'm kinda new here and this is my first time reporting an issue. You see, i was logging on to Minecraft in the Minecraft Launcher. Everything was fine and normal but the loading time was not how it's usually like, i usually had to wait for like 10 - 15 seconds or so to get my game to start. So i tried looking up some solutions and i found it, i uninstalled the launcher (and the installer) and reinstalled it. It was fine at first but i still had that problem so i kinda gave up. So time passes and i start up my computer again, determined to fix the launcher. When i opened the launcher, the launcher didn't open. It only displayed a text box saying 'Unable to load' bla bla bla program files, stuff like that.