How to fix error reading file on installer

OK so i just downloaded Unreal engine then i get this little error

error reading file from C:\OpticSpycrab\downloads\EpicGamesLauncherInstaller.msi Verify that the file is there and it exists.

Now how do i verify it when im using the darn thing

Hi Optic_Spycrab,

I’m sorry that you are having an issue with the Epic Games Launcher. In order for us to offer the best support, we have recently modified the process for how Epic Games can help troubleshoot your Launcher issue. Please visit http://help.epicgames.com/ for technical support, here you can find information and solutions for common issues, as well as a contact form if you still need additional assistance. Thanks!

If the error occurs after attempting to open a project/the editor via the .exe, try verifying your engine build by going to the launcher>library>engine dropdown context menu>verify. This will check your engine and repair/replace missing or damaged files.