To deselect all file types from the File Types list in the Indexing Options, there is a relatively simple workaround you can try.
1. Press the Windows key + R on your keyboard to open the Run dialog box.
2. Type "regedit" (without quotes) and press Enter to open the Registry Editor.
3. In the Registry Editor, navigate to the following location:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Search\Gather\Windows\SystemIndex\FullTextFilters
4. Right-click on the FullTextFilters key and select Export to create a backup of the key, just in case.
5. After creating the backup, delete the FullTextFilters key.
6. Close the Registry Editor and restart your computer.
By deleting the FullTextFilters key, you are effectively removing all file type associations from the Indexer, which means no file types will be indexed unless re-selected.
However, please note that modifying the Windows Registry can be risky, and any mistakes could potentially cause system issues. It's essential to back up your data and proceed with caution when making any changes to the Registry.
Additionally, keep in mind that this method will remove all file type associations, not only the ones you want to deselect. So, if you want to index specific file types in the future, you will have to re-associate them manually.