Computer wont connect

Hi i have just got my CNC 3018 pro I had a few problems to begin with but you helped me solve them. This is the reason i am coming back to you, for some reason all of a sudden my computer will not connect to my machine . I have reset my machine, restarted my computer, tried all my usb ports but for some reason it will not connect any ideas please.

Is the baud rate the same? Baud rate for grbl should be 115200

Yes the baud is the same.

You may need to tell it which com port to connect to. It may be hooked to com 2 and need to be hooked to com 3 or com 4 .Check and see which one it says it is hooked to.