This is what I was advised to do.
"Lol !
open any forum page, right at the top click "profile"
At the top of that page you will see "update postnuke profile" box
right click your image, then click "properties"
highlight the line that starts with http://
hold ctrl button and hit your "c" key
now go back to the post nuke box
type in ""
then while holding "ctrl" button, hit your "v" key
then "http://" line will appear
then type in "
scroll to the bottom of the page and hit "submit"
If you need to shring the image first
right click the image, click "edit" in the menu
this opens paint
click "image" then under the menu "stretch/skew"
this opens a box that allows you to alter size by %
when done click "save as" jpeg
then use as above!
Cheers
Hope it helps