@MrCParadise This file is a Windows AVI format support library. Errors may occur when installing new software, that utilize this library, fragmenting the Windows registry with invalid entries to this file.
The best solution is to search for AVI-related updates on the Microsoft website.
Hold on, read this first:
and certainly this one:
@MrCParadise Try manual install: https://windll.com/dll/microsoft-corporation/avifil32
@MrCParadise If you have anti-virus, try to exclude/whitelist the file. Provide the full path to the file. It may have been flagged as sus by your AV and EAC doesn't run if there's anything wrong with that file.
@VFG3070ti If you mean to reinstall the OS, then it's only the starting part of the solution. If it still doesn't work, just follow the other steps, building it up so to speak. I would say, try the other suggestions first, because clean reinstalling and reupdating everything is such a drag.
If I could also note, that verifing system requirements first before installing the game should be considered, since this might slip many people's mind, just like a common habit of scrolling down and not reading some program's User Agreement.
Nevertheless, hope it helps.
