Try this (it is probably a syntax problem with your host directory space or ISP or perhaps they don't allow linking)
OPTION A:
Find the image you want online --- right click --- save Picture as...
then name it and make sure you notice which directory it is located it when you save.
Goto Tractorforum USER-CP button up top of main page ----
Edit Options, Change Avatar, click on upload avatar from your computer [Browse], locate the picture you saved from steps above and click enter.
It should load it. Remember that your image must be 150x150 pixels max.
OPTION B:
If you want to make it easy, just give me a link to your image and I will download and resize and place it for you.
Smiles,
Andy