The smiley emoticons in the Yahoo instant messenger software are stored in a folder on your computer, so you can remove them even if you cannot get into the contacts section in your Yahoo email. Because the emoticons folder is separate from contacts, when you remove it, the images are not shown when you use the Yahoo IM client software.
Click the Windows "Start" button and type "yahoo" into the search text box. Press "Enter" to open the folder that contain the IM files. Double-click "messenger," then double-click "media."
Highlight each smiley you want to delete. To delete all of them, right-click the folder window and select "Select All."
Press the "Delete" key. Click "Yes" to confirm that you want to delete the files. Restart the software for the changes to take effect.