How to Remove Yahoo and Bing

I have tried countless ways to delete Yahoo and Bing search engines from my laptop but to no avail. Please..... is there anyone who can tell me how to do this? I have tried the options route on the toolbar, the add/remove programmes in the Control Panel and a piece of software downloaded from the internet which would 'clean' out malware. Nothing seems to have changed. I am supposed to be using Mozilla Firefox which is being listed as my default browser.
Here's hoping........... and with thanks in advance..........

topgundcp said:

In addition to the above. A little clearer with a pix:

Well....... thank you both for your help - especially helpful pix. It seems to have worked for today So if it is still working tomorrow I am truly truly grateful to you both. The difference this time when using this 'options' setting (which I have already tried) was that both Bing and Yahoo appeared on the list whereas previously they did not! I wonder why that is, but it is the reason I am a bit doubtful it will still be working tomorrow. However, for the time being thanks again for your resourcefulness.