Msimmsgr.dll is a process belonging to the Microsoft Exchange Messenger Service Provider program. Msimmsgr.dll error messages may show up on screen once your PC boots up or shuts down, or when users attempt to install or open a certain program without its required dll file. Such msimmsgr.dll errors are mostly caused by missing or corruptin the file of msimmsgr.dll. To fix it you just need to download msimmsgr.dll file, and install it on the place where it is missing or corrupted.

Common msimmsgr.dll error messages:
- "Windows could not start because the following file is missing or corrupt: Windows root\system32\Msimmsgr.dll. Please re-install a copy of the above file."
- "Winnt_root>\System32\Msimmsgr.dll missing or corrupt: Please re-install a copy of the above file."
- "Cannot find \Windows\System32\Msimmsgr.dll."
- "Cannot find Msimmsgr.dll."
- "A required .DLL file, Msimmsgr.dll was not found."
- "Program requires the file 'Msimmsgr.dll' to run. Run Setup again to assure proper installation."

How to install msimmsgr.dll file?

1. Press Start and select Run
2. Type CMD and press Enter (or if you use Windows ME, type COMMAND)
3. Type regsvr32 msimmsgr.dll and press Enter
4. In the end, you should receive a message saying that your file was successfully installed or uninstalled.