Since you are referring to an EXE file, which are not for Android, I assume that you are having issues with the desktop version of Firefox. If your Firefox installation is damaged, you should be able to reinstall Firefox from [https://www.mozilla.org/en-US/firefox/new the Firefox website] without losing your profile data, assuming that has not been damaged as well. If that doesn't help, you will likely get better support if you post your question in [https://support.mozilla.org/en-US/questions/new/desktop the Firefox desktop support website] instead.