i try to do the proxy setting also but i get the "unable to tunnel through proxy. proxy returns http/1.0 404 not found" ERROR! i do not find any way to resolve this problem if i do something wrong with hostname or port what i use hostname: login.salesforce.com port: 80
I think you have installed the version 36.0 of force IDE. If yes then there is a problem with this IDE. You can't create new object or save the old project.
I have also face this issue. I suggest you to install version 35. It will solve your problem.
When moving next in IDE installation there is one checkbox don't display previous version unchechk this checkbox and you will get list of all previous version. Install version 35 from there.