If you are searching for above Question answer that whether you can Change the Operating System of Nokia ,Samsung ,Sony Ericsson , LG ,MicroMax or any Mobile Phones then my answer is No.
An OS (operating system) is the means of operation of a device; iOS (Apple-iPhone), RIM (Blackberry), Symbian (Nokia) and the Android OS. What you are referring to is the on-board memory.
In most cases it is limited to about 125-250 MB. Newer devices are capable of going into GB, but that is usually the case with smart phones and multimedia phones. Memory cards only assist in the storage of media and not information like contacts.