I loaded the 7.6.7_win_x86-64(1).msi libre office and I can no longer start it.
I don't understand all the above. I just want to use Libre office. I'm a simple user who doesn't want to have to learn all the technical stuff.
And what is your Operating System?
OK, we'll try to be precise and clear for you. The .msi is a MS Installer package. When you "load" it you are actually installing LibreOffice. With defaults that is to "C:\Program Files\LibreOffice" folder, where there is a subfolder "program". The default install will place a launch button onto your desktop, and onto the Windows Start menu. That links to a program "soffice.exe" residing in the above noted program folder. Some minor differences between desktop locations for Windows 11, Windows 10 or earlier Windows flavors, but the essence is that you must launch the soffice.exe (typically from the shortcut launch button, or directly from the program folder). Do NOT launch the .msi installer package again, that only needs to be done once. On a successful launch LibreOffice will create a user profile held in you Windows %APPDATA% folder. By default at "C:\Users\<yourUserName>\AppData\Roaming\LibreOffice\4\user". You should check that it is created. Also be aware that you could delete, or rename, the folder to rebuild your LibreOffice profile with defaults. Please provide details of your operating system and desktop (i.e. just Windows 11 or Windows 10 is enough).