- If you don't already have it Google "Paint.NET", download and install it.
- Once you have Paint.NET installed open up your gif, for example:

- Click the magic wand
- Set the tolerance to zero
- Click the red area and you will see:

- Hit the delete key
- The result is:

Your gif is now transparent - Save your edited gif
Making a new transparent gif
- Create a new gif in Paint.NET of whatever size you require
- Click on the white background with the magic wand and with tolerance set to zero
- Hit the delete key
- The gif is now transparent
- Add your text or other graphics and save it.
Tip
If the image you are making transparent doesn't have particularly good sharp edges you may find it looks 'bitty'. In other words it hasn't cleared all of the background to transparency. If this is the case try experimenting with the tolerance setting. You shouldn't need to go higher than 40% though.