.mui file: how to open it on Windows

2 Windows apps register the .mui extension. Install one of them to open the file with a double-click.

• 
  Resource Hacker

  Resource Hacker is a program that allows you to compile and decompile various resources and file types.

  Free 5.2.8 143.4K ↓
• 
  RisohEditor

  Another free Win32 resource editor

  Open source 6.2.2 ★ 526

Related guide: Change the default app for a file type in Windows