Instructions
Start your PS2 system without a game disc, or with the cover in the open position. Press the blue "X" button on your PS2 controller to browse the system configuration menu.
Use the directional arrow buttons on the controller to select between the memory cards installed into your console. Press the blue "X" button to access a memory card.
You should see several rows of icons representing game saves that are stored on your memory card. Use the directional arrows to select any save file described as "corrupt;" press the blue "X" button on the controller to access the file. Press the down arrow key on your controller to select "delete" and delete the file. In some cases, you may need to repeat this procedure several times in order to successfully delete the file.