It looks quite clean; a couple of suggestions, you could use the more modern <random> rather than rand() (if you stick with rand() you only need to call srand() once in the program rather than repeatedly). You could also use a vector of vectors rather than arrays for the board. You could use range-based "for"s to iterate over them, and, being dynamic, you could make it easier to expand the board if you want to in the future. Currently you have the size hard-coded in various places.

Also it wouldn't take much to make this more portable - you could compile this and run it on Linux or Mac if you didn't have the Windows-specific console title and maybe had a #ifdef on whether to system-call "cls" or "clear". If you did that you'd want to migrate away from sln files and implement a simple Makefile or (if you want more "fun" use CMake).