You can use Microsoft Publisher to make transparency, Just make sure no other thing in the pic is the same color as the background. Insert the pic on microsoft publisher. There should be a option to set a transparent color. Click on the background. Voila!
Visit this site to get rid of the background -> http://www.iaza.com
You'll need to make the background of the picture red or another color first (it has to be a color that's not already in the picture.) The transparent option is the top one in the last column, it's hard to miss. You'll also need to convert it back to png when you're done as it will become a gif when you change it. (making it a png again will not bring back the background.)