The bug about full and demo versions of MC Win 10 ED

Theres a bug : I downloaded demo then i delete it and purchase win 10 edi . When i installed it looks like demo . Then i delete it and restart my computer. I downloaded it again. It Works but i shutted down my computer and open it. It looked like demo version again . i delete it again and restart my computer. I downloaded it again.It Works . I dont want to do when i open every day. My english isnt good sorry. but i think old demo datas cause this.
can you help?