How to attach an image to a mp3 file?

Hi, I'm Mario, and I'd be happy to help with your issue.
We are sorry about what happened.

I'm not sure I understand your question very well.
Follow the steps below to add the song cover to the file:

METHOD 1 - Add the album cover (or track art) manually using Windows Media Player 12.
1. run Windows Media Player.
2. Click the Music tab.
3. Drag the image you want to add to the Album Art (album cover) icon.
The image will be added as the album cover.

METHOD 2 - Add the album cover (or track art) manually using Windows Media Player 11
1. run WMP.
2. Click Library on the top bar.
3. Right-click the file(s) you want to update and select Advanced Mark Editor.
4. Click the Image tab, click Add.
5. Browse to the image you want to use as the album cover, and then click Open.
6. Click Apply, and then click OK.

METHOD 3 - Let WMP find the Album Information (WMP 10 and 11)
1. run Windows Media Player.
2. Click Library on the top bar (left bar for WMP10).
3. Right-click the file(s) you want to update.
4. Select Find Album Information.

Kind Regards,
Mario B.