Is there multiple slots to install the Memory? Could be that the slot you are using is bad. That or the memory isn't currently seated all the way in the slot.
Possible that your memory needs to be re-seated in the slot. Try and re-seat the memory and then reboot. If that doesn't work.. Check to see if any lights flash/light up in a certain order. Look up Toshiba Satellite M45 error codes and try to figure it out from there.