Help With Avatar Please

[VinnieOlle]

i made myself an avatar in paint.
When i try to upload it it says:
"An Error Has Occurred!
The attachments upload directory is not writable. Your attachment or avatar cannot be saved. "

What do i do?

EDIT: I used an image hosting site and took their link for it and now it works.
BUT: i made it thinking that avatars could be 128x128 now i have to edit it!