FileTypesMan 1.55 is a File Management product from nirsoft.net, get 4 Stars SoftSea Rating, FileTypesMan is an alternative to the 'File Types' tab in the 'Folder Options' of Windows. It displays the list of all file extensions and types registered on your computer. For each file type, the following information is displayed: Type Name, Description, MIME Type, Perceived Type, Flags, Browser Flags, and more.
FileTypesMan also allows you to easily edit the properties and flags of each file type, as well as it allows you to add, edit, and remove actions in a file type.

FileTypesMan doesn't require any installation process or additional DLL files. In order to start using it, simply copy the executable file (FileTypesMan.exe) to any folder you like, and run it.
After running it, you should wait a few seconds until the file types list is loaded. If the loading process is too slow, it's recommended to turn off the icons loading (Options->Don't Load Icons in menu), so in the next time that you run FileTypesMan, the loading process will be faster.
The main window of FileTypesMan contains 2 panes. The upper pane displays the list of all extensions/file types registered on your computer. When you select a single file type in the upper pane, the lower pane displays the list of all actions of the selected type.

'Replace File Type For Selected Extension' option (F4)
Sometimes, when you install a new software, it automatically replaces the file types associated with various file extensions. This means that when you double-click the file, the new installed software is opened, instead of the old one. The icon of the extension is usually also replaced to the icon of the new application.
The 'Replace File Type' feature allows you to set the file extension back to the original file type. In order to do that, select the desired file extension in the main window of FileTypesMan, and press F4. You'll get a long list of available file types on your computer. Find and select the previous file type that handled the extension, and choose 'Ok'.

Desktop Refresh
Each time that you make a change in the properties of a file type, FileTypesMan automatically initiate a general desktop refresh, so your changes will take affect immediately, even for opened Explorer windows. However, on slow computers, this desktop refresh might consume a fair amount of CPU resources, and even hang the entire operating system for a few seconds. If you want to avoid this desktop refresh on every change that you make, simply disable the automatic refresh, by unchecking the option under the following menu: Options->Automatic Desktop Refresh.
You can always initiate a desktop refresh when you need it, simply by selecting 'File->Refresh Desktop Now' from the main menu. The license of this file & disk software is Freeware, you can free download and free use this File & Disk software.