My skin becomes very dry during winters. I have used different creams but then also my skin becomes dry. Why it happens and how can it be cured.

Buy a good... ...Emollient lotion (keri, lubriderm, aveeno, (oatmeal) neutrogena, whatever), and apply after you bathe, while your skin is still moist. Dry skin is not something you can "cure", per se, but it can be controlled.