C++ Register & Login Problem + How to store data permanently?

Every time your program starts up, all of the variables will be new in respect to the last time your program was run. In order to save data you will have to write it into a file. An easy way to do this is to use the fstream library. You can open() a file and output data to it, then when you run your program again you will have to open the file and read in the data.