Amir,
I am afraid the issue you are reporting with Windows Word replacing MyEclipse view is not a MyEclipse issue. Please check your OS settings.
In MyEclipse 2015, the server connectors are available from New > Other > Server. If you want to work with any server, you should first create a runtime for that server from Window > Preferences > MyEclipse > Servers > Runtime Environments.
Alternatively, you can also add a new runtime by clicking on ‘Configure runtime environments’ in the ‘New Server’ wizard.
Once the server runtime is added, point to it in the ‘New Server’ wizard to complete configuring the server.
Here is the screenshot for your reference :
Let us know if you see any issues.