Try this: Click on User CP to get to the are where you can edit in the Settings & Options.
Click on Edit Avatar
Click the button Use Custom Avatar
Click the Browse...button
Choose your pic from your computer and select it and open it
Once back at the Edit Avatar page, click on Save Changes
If it doesn't work, then your pic is too large
Try to make it smaller by right clicking the pic on your computer when it is in icon form and see if there is an option to Resize the picture
If there is, make it smaller and try that
If it's still not working, you'll have to ask a pro...but hey, I tried
Good Luck!