Follow these steps Jacqui and you should be ok.
(1)  The picture you wish to use must be 
65 pixels x 65 pixels  in size.
(2)  Save it with a file extension of 
.gif.
(3)  I presume you have been allocated some web site server space from your Internet Provider, so you need to upload the pic there .
(4)  Then go into your Forum Profile, and under the section 
Personalized Picture   select 
Specify avatar by URL.
(5)  An example of the URL path to use to see your piccy is shown to the right of that selection.  So for example, if your server domain is called 
mydomain.com, and you save all your images in a folder called 
images, and you name your Forum pic 
mypic.gif, then the full path to enter here would be:
http://www.mydomain.com/images/mypic.gif.  (Don't click this sample link as it's not an active one  

 )
(6)  Click the 
Change Profile   button at the bottom to save your changes.  You should now see your profile pic.
If you have any problems just let us know  

Laurie.