Whenever you post something on the forum a small image is displayed to the left of your post beneath your display name (username). This is called your Avatar or "Display Picture" - to change this, simply make sure you are logged in to the forum click on PROFILE at the top of the page, then click MODIFY PROFILE.

Scroll down to Your Information and click [Upload] next to the Avatar URL field.
Browse for an image on your computer, or enter an image URL. Then click Insert Avatar and to save your changes click Modify Profile on the bottom of the page.

It doesnt work! ive been trying for like....half an hour now. Grrrr......

Can anyone help pse?

Make sure you're clicking Upload, after choosing an image. Then wait until it says File Uploaded

Finally, click Insert Avatar and then Modify Profile at the bottom of the page to save the changes.