Linux is not Windows and doesn't work with drive letters like Windows does. Instead it uses mountpoints (directories) where you can mount your partitions and access the data on them just by browsing that directory. When you say 'change to drive' are you looking for your second drive using the graphical environment or in a terminal? Can you indicate what distro (Ubuntu, Debian, ...) and version you're using and if graphical environment what desktop environment (Gnome, KDE, ...).
To get some basic information about differences between Linux and Windows, all explained in simple words, have a look at these sites:
Linux is not Windows
Linux frequently asked questions for newbies