When the command prompt opens and then just closes really fast (because there isn't a pause line) is there a way to see what it just showed you?
Not after the fact, no. Once it's gone, it's gone. If you have the luxury of being able to run it again (i.e., you know what program or command was executed), then you can use some of the other suggestions noted here, and then count on the output from your run being the same as it was in the previous run. Suggestions include running the command in an already-open console window, piping the output to a file so you can read it later, and running the program in a batch file that has the pause command afterward.