Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The LD2 file type is primarily associated with 'Lingoes' by Lingoes Project.
Lingoes is dictionary and text translation software.
It offers lookup dictionaries, full text translation, capture word on screen, translate selected text and pronunciation of words in over 80 languages.