Guys, i need help, im new in mikrotik, i have a mikrotik 433 board and I believe it already have router os built in to it, ive been trying to access it using serial console with the use of secure crt, I can connect to the router but its not showing me anything.. Ive tried using winbox and its not working too, can somebody recommend the best way of accessing router os (NAND) thanks.

Yes, all routerboards have preinstalled RouterOS.
Make sure you are using correct baud rate.
http://wiki.mikrotik.com/wiki/Serial_Console

thank you for the answer, yes my baud rate is correct, however im using a serial to usb console, will that be an issue, one more thing, I also installed router os 3.25 on vmware and I can access the router configuration from there, does that mean that it supercedes the original operating system of the routerboard?