Okay we posted at the same time.
I guess you are talking about the Avatar upload now.
You need to start at
Control Panel » DB, Paths & URLs
Select the Paths& urls tab
This will give you a clue for a starting point on the two path settings.
Full url will be like http://mysite.com/avatars
Absolute path will be like /home/public_html/avatars for the Avatar Upload Storage Directory:
You also may need to check your file permissions at
Control Panel » Permission Checks
Make sure they all are okay