I have some questions with answers but non of the answers are acceptable (just wrong).
But after there are answers it is considered as answered, so I don't get any other answers.
Is there a way to remove answers that aren't helpful ?
You can down vote them. However, I would generally reserve this just for answers that are blatantly wrong or show that they really didn't read the question. For those that have some value but aren't the exact solution, often a comment can get them to edit their own answer to make it better or potentially delete it if they realize it's no good at all. You might also try editing your own question to add detail and make it clear what you are looking for.
Another option is to offer a bounty. For details please see the FAQ under the section "What if I don't get a good answer?"
In response to your questions specifically: Of the 28 questions you've asked on SO, only 5 seem to have answers you haven't accepted.
The first appears to have a correct answer, you just don't like the implementation.
The second has some thoughtful answers. In the comments you were asked to elaborate - which you did, but IMO it still isn't very clear exactly what you are looking for
The third has an answer that you didn't like, but when you were asked to elaborate further, you didn't.
The fourth is a question you provided the answer to but have not yet accepted
The fifth is probably the question you are referring to. You asked it twice, updated it multiple times, awarded a bounty, and provided a lot of feedback in the comments. SO is generally a great resource for talking with experts. However, perhaps this is a time when contacting Microsoft Technical support would be a good idea. Just removing the answers probably wouldn't make an expert skilled enough in your issue suddenly appear.