Do you still have both instances installed?
What error message are you getting when you try and connect to the default instance? To the named instance?
No, I uninstalled the instance installation ans install new one as default.I do not get any error but I can not connect to.I mean when I want to connect, “database engine” , the local machine is not one of the options.I just can connect to other servers!
I guess as adefault it should recognize the local machine,right?