Hi!

Have you tried copying the files you backed up back to the images folder?

If you lost your original files, backup the LDW folder (it's on My Documents) and reinstall the game. Them copy the LDW folder you backed up to My Documents again and continue playing.

To delete a mode safely, just copy the file from the backup you've done, with the same name as the mod, back to the Images folder. When the computer asks if you want to replace the file say yes.

If there are any more doubts, please do ask. Hope I was helpful.