Check the memory on windows:
1-Check the available memory left on the latop and try to close any unseeded applications. This should save for you 2 gigas additional and say 2 giga for the OS. 2-If this didn't work then please reduce the database memory assigned for the SGA to 1.5 or 2 giga although oracle recommends that the memory to be 2 giga at least but since it is for education then lets try that. I think if you do this it would be ok however i still think 8 giga RAM would be enought to assign 2 giga memory for each database and run ok.I have installed oracle RAC on a laptop similar to that one before and everything was going ok.
Please user ALT+CTRL+DELETE to see where your OS memory is consumed on windows machine.