How to change my profile in bitcointalk? thanks for the answers... 
Why can't I change my avatar?
Only Full Members and up are allowed to wear avatars. It must be no more than 120px wide, 80px tall, and 100 KiB in size. It must be a PNG, GIF, or JPEG image. It must be safe for work.
For more information why this restriction exists, please checkout About the recent attack and Avatars re-enabled
Read more here bro: https://bitcointalk.org/index.php?topic=1689727.0