Windows 7: How to change file Icon in Windows Explorer (.mp3)

Downloaded 15 mp3 audio files for learning English from British Council website. 13 files show beautiful artwork on the Windows Explore and Media Player as well same with the one on the webside. Howeer 2 files shows Windows defualt image of eighth note. I can not see any information about the icon in the property of the file. I wish to get some help to solve the my problem.

if you want to change file type icon, right here: File Extension Icon - Change Default Icon

If you want to add artwork or info to mp3 files, you can add it manually by using media players like aimp3 or foobar etc. in which they have features to insert artwork, lyrics, infos etc.

can you post a link to the images or the downloads,
we can extract the image for you and then re-post it for you.
use mp3tag to add artwork its very simple to use.

Mp3tag - the universal Tag Editor (ID3v2, MP4, OGG, FLAC, ...)

Dear Boohbah
I tried mp3tag application and it made me very happy.
Thank you

Dear Boohbah
Mp3tag worked happily, but I got new problem after the work.
1. Windows backup skipped audio file directory I worked with and appear error code 0x80070002F.
2. So, I removed covers form all *.mp3 files.
3. Then, I tried "Windows Backup" once again, but same error occurred.
4. Next step, I moved all cover art files *.jpg files from my computer to removal USB storage.
5. In spite of no art cover files in my computer, each artcover will appear when it is played under Media Player.
6. I can not see any information about cover art in the file property.
7. Then foolishly I tried to convert the file from *.mp3 to WMA2, but result was same.
I have no further idea to try something.
Looking forward to the pleasure of hearing some hints or idea from you.
Regards.