Can i isolate my pic from my pc's noise by using 2 optocouplers and
>powering the serial comms from the serial port as in the schematic?
>
>formatting link
Might work, bot not guaranteed. This circuit requires your serial port voltage levels to be some
9 volt. They often are, but can be as low as 5 volt. If your PC is a laptop, it is not likely to work at all.
If you have the option: an ethernet port on your PIC would be a far better solution.