Originally posted by iusehacksv1
I transferred the game over to my internal HDD
Try deleting it from the Internal HDD. After it is done, go to File Manager in the last tab on the left. Double click PS3 Root. Navigate to dev_usb and go inside it. Then find the folder of the Modern Warfare 3 game, copy it, go back by pressing the three dots at the top until you reach the dev_ page. Double click on dev_hdd0, then double click the GAMES folder, then press Circle and paste the folder there.