1. Go to http://www.blogger.com/home (log on). You'll see a list of your blogs.
2. To the right of each blog name, there are a set of actions you can do for that blog. There's a little inverted triangle ("more options") among them. Click on it to see the options for the blog
3. Select "Settings" (the bottom option)
4. Click on "Posts and Comments"
5. Change the setting "Show Word Verification" to "No".
6. Save your changes!