How to stop an email from someone?

How can I stop someone who highjacked my yahoo messegner but is not active on my said accounts email?

• My yahoo messenger got high jacked or hacked into but the other area's of my account are not tampered with i.e. mail and yahoo answers which I don't understand. I know its a former friend of mine but i don't want to give up this email account because I don't want to re do all the work I have done on it i.e. recently becoming level 2 on here it's important to me to help others out and gain knowledge myself but I don't want to give up my stats as this is a hobby for me haha. So how do I stop him from using my yahoo messenger without deleting my email account. I have gotten answers from a similar question stating to uninstall my messenger but the person hacking me has messenger so I don't see how that would stop said person. I've changed passwords and he's figured them out, so how can I protect myself since he's pretending to me be and trying to ruin my relationship with my fiance! Please don't suggest confronting this person thats not my way I just want to prevent him hacking me

• Answer:

  If he is that good at getting your password even once you have changed it you might want to run a Virus,spyware/malware scan on your PC to make sure he didn't put a key logger on it ?? If you come up clean I would change my password again daily for at least the next week or so and Don't make it easy to guess or close to what it is when you change it. Make it something really off the wall different!!! Oh and by the way uninstalling it and doing a re-install won't solve a thing, it'll just waste your time! hope this helps