The msi.dll is a dynamic library link that is part of a Microsoft Installer application. This component is most commonly used with MSI files and helps with the installation or uninstallation of Microsoft operating systems or Windows apps. It can appear in almost any application, so it can be difficult to track down the problem. See below for some troubleshooting steps you can take to fix the msi.dll not found or missing error.

Recover msi.dll from Recycle Bin. The simplest possible cause of a "missing" DLL file is that you accidentally deleted it.

If you suspect this, but you've already emptied the Recycle Bin, you may be able to recover the file with a free data recovery program.

Run a virus/malware scan on your entire system. Some msi.dll errors could be related to a virus or other malware infection on your computer that has corrupted the file. It's even possible that the error you're seeing is related to a hostile program masquerading as the file.