Does anyone know how to block unwanted posts from posting to WordPress blog?

Np. I used another but I was told it is good. Let me know.

Thank you, Harry. I am using WP Anti Spam now. Hopefully it will do the trick. ^_^

Try this plug in WP Anti Spam, you can block by many different ways. I used one that blocked bots that I have to find on one of my money sites but I have a few hundred so it will take time.

I found 2 Spam plug ins: Spam IP Blocker and WP Anti Spam. WP Anti Spam blocks spam by "comment","ip","name","email","url". I am hoping these will work well together.
Thank you everyone for your input and assistance. They were all very much appreciated.

Thank ELAP. I will give Livefyre a review.
Thank you Cheri but that was the setting and the unwanted posts still barged through. I had the settings on approval only so all comments had to first go through me before they could get posted but somehow this bot got through. I am looking for advanced features in combating spam bots.

Under settings - discussions you can control unwanted post. Uncheck anyone can post for instance.

Also I thin k if you are little experience you can use livefyre to your WP website and not only you will completely block unwanted comments you also will make live chat and discussinon on your WP website. Will make good credibilty to you and to your website. Thank you take care.

I have Askimet...it's not working.

Install Askimet. Its a WP plug in. You need a free account to get the key in order it to work. It blocks most of them.